Chemistry

ResourcesQuestionsChemistry

A photon interacts with a ground state electron in a hydrogen atom and is absorbed.

I have all of the answers except this one........... A photon interacts with a ground state electron in a hydrogen atom and is absorbed. The electron is ejected from the atom and exhibits a de Broglie wavelength of 5.908×10−10 m. Determine the frequency (in hz) of the interacting photon.

anyone want to help?

Elise

A solution is a mixture of a liquid (the -----) and a dissolved solid (the ----). When no more solid can dissolve, the solution is -----. The dissolved solid may then begin to reappera; we say it has -----.

A solution is a mixture of a liquid (the -----) and a dissolved solid (the ----). When no more solid can dissolve, the solution is -----. The dissolved solid may then begin to reappera; we say it has -----.

Anish

About exam

Day after tomorrow is my exam. I have covered all most all the chapters in chemistry. But I am confused that how to revise all chapters just a day before exam. Please help.

Emma-Jayne

Acid base titrations

I'll attach the question and my working in the below

Djon

Acids and Bases

For the chemical compound which is represented in vinegar together with water: What is the name and formula of this compound?

Kulwinder

Acids and Bases

When copper metal reacts with concentrated nitric acid, SALT, WATER and GAS forms. What is the name of the gas?

Keighly

Additional polymerisation - How does it work?

Additional polymerisation - How does it work?

Gabrielle

alloys / moles

You need to cast an alloy of titanium (Ti) containing 46 at.% aluminium (Al). Using the information from your periodic table, estimate how much Ti and Al you will need to put in the crucible in order to cast a 100 g ingot of this alloy. b) By mistake, you added to the crucible 32.4 g of Ti and 67.6 g of Al. Work out the composition of your ingot in at.%.

Aamna

AS Chemistry Unit 1

I'm struggling with the calculation questions, know if you anyone could do a solution going through them?

Shmiela

Balance an symbol equation between methane and oxygen.

Balance an symbol equation between methane and oxygen.

Jody

Balancing symbol equation

what is the balanced symbol equation for iron oxide add magnesium and how do i figure it out

Alis

Biochemistry

Explain the interplay between enthalpy (H) and entropy (S) changes taking place during ligand binding. someone help please

Allan

Boiling Point

What is the boiling point of Styrofoam (polystyrene)? NOT MELTING POINT

Cherry

Bunsen burners

What are them types of flames

Barry-John

calcium oxide

calcium oxide

Karen

Calculations

The fHo of Ethanol (CH3CH2OH) (l)), Water (H2O (l)) and carbon Dioxide (CO2(g)) at 298K are respectively; -277.1 kJ mol-1, -285.8 kJ mol-1 and –393.5 kJ mol-1. Given that the latent heat of fusion of water is 6.02 kJ mol-1 and the average heat capacity of water is 75.3 J K-1 mol-1 how much ice (in grams) would be needed to put in a measure of whisky (25ml, 40% ethanol by volume) such that all the enthalpy of combustion of the ethanol is taken up raising the temperature of the ice to body temperature (35C). Density of ethanol = 0.789 g cm-3 (16 marks)

Sherrell

Can anyone help

I have a diff problem .......Titanium (Ti) can be produced by the reaction of metallic sodium (Na) with titanium tetrachloride vapor (TiCl4). The byproduct of this reaction is sodium chloride (NaCl). Calculate the amount of titanium produced (in kg) when a reactor is charged with 73.0 kg of TiCl4 and 10.0 kg of Na.

Heathel

can u discribe some properties of solids and liquids please

can u discribe some properties of solids and liquids please

Frazer

Can you tell about hydrogen as a fuel?

How is hydrogen used as a fuel? How is it produced? What are the advantages and disadvantages?

Shawn

Catalyst equation help

A catalyst consisting of palladium on an α-Al2O3 support, Pd/α-Al2O3, has been used for the oxidation of CO at room temperature:

Equation 1 CO(g) + ½O2(g) = CO2(g)

Under certain conditions, the oxidation reaction was found to involve competitive adsorption of the reactants with CO being non-dissociatively adsorbed and oxygen undergoing dual-site adsorption:

Equation 2 ka CO(g) + * ↔ CO(ad) Kd

Equation 3 ka’ O2(g) + 2* ↔ O(ad) + O(ad) kd’

The rate-limiting step is then a bimolecular reaction between CO(ad) and O(ad):

Equation 4 CO(ad) + O(ad) → CO (ad)

Carbon dioxide can be assume to be weakly adsorbed and, as a consequence, desorbs as quickly as it is formed.

(i) For the competitive adsorption of CO show that the following expression can be derived by equating the rates of adsorption and desorption of CO:

Equation 5 θCO = bCOpCO(1 – θCO – θO)

Where θCO and θO are the fractional surface coverages of CO and O, respectively. The quantity bCO (= ka/kd) is the adsorption coefficient for CO and pCO is the partial pressure of CO. (Hint In your working you should represent the total number of adsorption sites by N and provide expressions for both the rate of adsorption and the rate of desorption of CO.)

(ii) Equation 5 can be used in a more detailed analysis of the mechanism to derive the following two expressions:

Equation 6 θCO = (bCOpCO) / (1 + bCOpCO + (bO2pO2)1/2)

and

Equation 7 θO = θCO((bO2pO2)1/2 / bCOpCO)

where b02(= ka’ / kd’) and pO2 are, respectively, the adsorption coefficient and partial pressure of O2.

Given Equations 6 and 7, in conjunction with the information about the rate-limiting step at the start of this question, show that the theoretical rate equation takes the form:

Equation 8 r = (kθbCOpCO(bO2pO2)1/2) / {1 + bCOpCO + (bO2pO2)1/2}^2

(iii) The experimental rate equation for the CO oxidation reaction, under conditions for which the mechanism given in part (ii) is valid, takes the form:

Equation 9 r = (kR(pO2)1/2) / pCO

How can this result be rationalised in terms of the theoretical rate equation (Equation 8) that has been derived for the mechanism?

Pagaine

Catalyst equation help (redone)

A catalyst consisting of palladium on an α-Al2O3 support, Pd/α-Al2O3, has been used for the oxidation of CO at room temperature:

Equation 1 CO(g) + ½O2(g) = CO2(g)

Under certain conditions, the oxidation reaction was found to involve competitive adsorption of the reactants with CO being non-dissociatively adsorbed and oxygen undergoing dual-site adsorption:

Equation 2 ka CO(g) + * ↔ CO(ad) kd

Equation 3 ka’ O2(g) + 2* ↔ O(ad) + O(ad) kd’

The rate-limiting step is then a bimolecular reaction between CO(ad) and O(ad):

Equation 4 CO(ad) + O(ad) → CO (ad)

Carbon dioxide can be assume to be weakly adsorbed and, as a consequence, desorbs as quickly as it is formed.

(i) For the competitive adsorption of CO show that the following expression can be derived by equating the rates of adsorption and desorption of CO:

Equation 5 θCO = bCOpCO(1 – θCO – θO)

Where θCO and θO are the fractional surface coverages of CO and O, respectively. The quantity bCO (= ka/kd) is the adsorption coefficient for CO and pCO is the partial pressure of CO. (Hint In your working you should represent the total number of adsorption sites by N and provide expressions for both the rate of adsorption and the rate of desorption of CO.)

(ii) Equation 5 can be used in a more detailed analysis of the mechanism to derive the following two expressions:

Equation 6 θCO = (bCOpCO) / (1 + bCOpCO + (bO2pO2)1/2)

and

Equation 7 θO = θCO((bO2pO2)1/2 / bCOpCO)

where b02(= ka’ / kd’) and pO2 are, respectively, the adsorption coefficient and partial pressure of O2.

Given Equations 6 and 7, in conjunction with the information about the rate-limiting step at the start of this question, show that the theoretical rate equation takes the form:

Equation 8 r = (kθbCOpCO(bO2pO2)1/2) / {1 + bCOpCO + (bO2pO2)1/2}^2

(iii) The experimental rate equation for the CO oxidation reaction, under conditions for which the mechanism given in part (ii) is valid, takes the form:

Equation 9 r = (kR(pO2)1/2) / pCO

How can this result be rationalised in terms of the theoretical rate equation (Equation 8) that has been derived for the mechanism?

Ceylan

CHEM

i need to be able to write the formula for each compund based on the name and ionic nomenclature as well so for instance CuSO4 and Iron(ll) oxide

Oystein

Chemical name

Were i will write -um,-us , -ide etc. End of any chemical name

Arianna

Chemistry

What happens to stearic acid and paraffin wax at a molecular level and the velocity of molecules when it solidifies and melts?

Nickos

Chemistry A-level Help

I need help with my Chemistry AS A-level - looking for weekly tuition to cover the OCR A Exam board. Can anyone help?

Thanks, Bobby

Seamus

Chemistry A Level tutor needed as soon as possible

I need additional help for my final year in A level in chemistry to reach my target grade. Can any one tutor Sundays ?

Shuna

chemistry heeeeeeelp

(a) A pressure vessel contains a large volume of CO2 gas at 10 atm pressure. A membrane composed of a poly(ether ketone) polymer with thickness 100 microns and net effective area of 100 cm2 covers a small perforated port in the container. The solubility of CO2 at 10 atm is 6.97 x 10-4 moles/cm3 at 35 C. The diffusivity of CO2 in the polymer is known to be 2.29 x 10-8 cm2/s at this temperature.

How long will it take for 0.001 moles of CO2 to leak from the container at steady-state? Assume that the amount of carbon dioxide in the surroundings is insignificant. Express your answer in hours.

(b) If the diffusivity is observed to double when the temperature is increased by 10 degrees C, what is the activation energy for diffusion? Express your answer in units of eV

Charlotte

Chemistry help

Sulfur vapor is analyzed by photoelectron spectroscopy (PES). Measurements determine that photoelectrons associated with the 1st ionization energy of sulfur move with de Broglie wavelength λ=5.091 A˚. What is the maximum wavelength (in meters) of radiation capable of ionizing sulfur and producing this effect?

Koon

Chemistry/Biology

Seeking an experienced tutor, preferably with teaching experience and knowledge of both Chemistry and Biology (chemistry being the primary subject) A2 level AQA Board. Tutor needs in-depth knowledge, importantly to convey and teach the subject matter in an understandable, friendly and patient manner. From experience chemistry is particularly challenging with the absence of person to person interaction. Organic chemistry has been difficult to grasp. Also to help build and gain confidence and exam technique.

Fred

Covalent bond

What is a covalent bond?

Rikki

Cracking Hydrocarbons?

At school or revising at home I had no idea about cracking, what the process is or how it works, I nead help fully understanding. I am on higher tier for GCSE science. Thanks a lot.

Paisley

Cu(OH)2 and d.H2SO4

Will Cu(OH)2 react with dilute sulfuric acid?

Ruth

Dalton's Law of partial Pressures

A sample of butane was collected over water. If this occurred at STP, what was the partial pressure of the butane?

Allisia

Describe the occurrence of the neon and the processes involved in its extraction.

Describe the occurrence of the neon and the processes involved in its extraction.

Zara

Dilutions (w/v) really need help with this!?

In order to prepare for this lab exercise one would be required to prepare 1.0 % (w/v) NaCl. Based on this lab exercise answer the questions below based on the diluents. a) How much diluent would an individual student require to complete this lab? Support the answer with relevant calculations.

b) One was instructed to prepare enough diluent for a class of 24 students. In determining the total amount of diluent needed each student would typically require slightly more volume. Assume that each student will take 25 % additional volume. Calculate the amount of diluent needed for a class of 24 students. Show using a labeled diagram how one would prepare the diluent.

can anyone help me with either one or both questions please!

Giuliana

Do you need Maths A-level to study Chemistry at University?

Not really, though it would be helpful. If you love science, specifically chemistry, but aren't a maths fan it is possible to a) get a place at a good university b) do well on the course.

At degree level, chemistry is roughly divided into three areas, organic, inorganic and physical. The first of these only require GCSE level maths for small parts of the course. Physical chemistry also largely only requires this level, but some integration/differentiation is necessary, and certain modules are more maths heavy. So well over two thirds of your degree would be science only, and the final third would be science with a bit of maths!

That said, having maths A-level is still advantageous, and some courses require it. Universities such as the University of Bath offer top up maths courses so you can learn just the bits you need when you get there.

If you also love maths, then you will enjoy chemistry, but why not consider chemical engineering? This is largely about designing factories to make chemicals on a large scale, but also devices such as solar cells, deodorant cans, and football stadiums.

Asif

draw a table to show the differences between solids, liquids and gases. use these headings: keep its shape, keep its volume, flows,how dense it is

draw a table to show the differences between solids, liquids and gases. use these headings: keep its shape, keep its volume, flows,how dense it is

Musammat

electric charge

two identical charges each of 15g mass and negligible volume are both suspended from the same point by a non conduction weightless strings 1500mm in length. Find the magnitude of each charge is the angle between the strings is 5.

The answer to this question according to the back of the book is 0.11x10^-6C.

Courtney

energy change

what is the relationship between volume and the amount of energy transferred as heat

Flora

Enzyme Kinetics/ Biochemistry

You do a set of enzyme assays, plot a Lineweaver-Burk plot and estimate a Vmax reaction rate of 20 μmol.L-1.s-1 when the enzyme concentration is 10 ng.mL-1. Assuming that your enzyme is pure, that you have 20 mg of it and its Mr is 50,000:- - how many enzyme units do you have in total ? - what is the specific activity ? - what is the kcat ?

Marium

Equilibrium Constant

The last step in the biochemical pathway of glycolysis is:

Phosphoenolpyruvate + ADP Pyruvate + ATP

Its Standard Gibbs Free Energy, ΔGo, at 25C is -31.4 kJ.mol-1.

What is the equilibrium constant, Ke ?

(ΔGo = - RT ln{Ke}; R = Gas Constant = 8.3145 J.K-1.mol-1 ; T = absolute temperature)

If all reactants and products are at equal concentrations, in which direction will the reaction move naturally i.e. left or right ?

Kristoffer

Estimate the 4th ionization energy of beryllium (Be). Express your answer in Joules (J/atom).

Estimate the 4th ionization energy of beryllium (Be). Express your answer in Joules (J/atom).

Jijay

Gas phase reaction help

The gas-phase reaction between trichloromethane, CHCl3, and chlorine, Cl2, has time-independent stoichiometry and can be represented as follows:

Equation 1 CHCl3(g) + Cl2(g) = CCl4(g) + HCl(g)

Under certain experimental conditions, the experimental rate equation was found to be:

Equation 2 J = kR[CHCl3][Cl2]^1/2

A three-step mechanism has been proposed for Reaction 1:

Equation 3 k1 Cl2 ↔ 2Cl• k-1

Equation 4 k2 CHCl3 + Cl• → HCl + CCl3•

Equation 5 k3 CCl3 + Cl• → CCl4

(i) Explain why the form of the experimental rate equation indicates that Reaction 1 cannot be an elementary reaction.

(ii) With reference to the three-step mechanism (Equations 3–5 ), and assuming that the second step (Equation 4) is rate-limiting, derive the chemical rate equation for this mechanism and then compare it with the experimental rate equation given in Equation 2.

(iii)The activation energy for the forward reaction, Ef , of step 1 (Equation 3) is 243.4 kJ mol^-1. Given this information, determine the activation energy for the reverse reaction, Er, and comment on the significance of the value (one sentence only).

Lianna

Help

The fictitious compound, arrhenium fluoride (AfH ), reacts with itself to form a dimer with the formula Ah2F2 . The reaction is second order in AhF. The value of the rate constant is 8.591x10-3 M-1s-1. What is the initial rate of reaction in a reactor filled with AhF to a concentration of 5.5M ? Express your answer in M.s-1.

Wing

Help

The half-life of a first order reaction is determined to be 85.5 years. How long will it take for the concentration of the reactant to reach 2% of its initial value?

Gabriella-Dawn

HELP!!!

At temperatures above 930 ∘C, PbO reduces PbS to form metallic lead (Pb). The byproduct of the reaction is SO2. Calculate the amount of lead produced (in kg) when a reactor is charged with 487.0 kg of PbS and 750 kg of PbO.

Ragu

Help Help Help

You wish to increase the carbon content of a slab of steel by exposing it to a carburizing atmosphere at elevated temperature. The carbon concentration in the steel before carburization is 359.5 ppm and is initially uniform through the thickness of the steel. The atmosphere of the carburizing furnace maintains a carbon concentration of 6695.0 ppm at the surface of the steel. Calculate the time required to carburize steel so that the concentration of carbon at a depth of 38.0 x 10-2 cm is one half the value of the carbon concentration at the surface. The diffusion coefficient of carbon in steel is 3.091 x 10-7 cm2/s at the carburizing temperature. Express your answer in hours.

DATA: Error Function Values erf(ξ

Stacy-Ann

Help needed TODAY

I need some help with biochemistry level 3 today. Any help would be appreciated

Samson

how are fossils formed

how are fossils formed

Jacquie

how does a basic synapse work?

how does a basic synapse work?

Baktash

How does this suggest the charge of the hypochlorite ion in the compound is calcium hypochlorite?

The calcium ion has a charge of 2+ (Ca2+)

Marvin

how is polythene made?

how is polythene made?

Sherylann

how many degrees of freedom do Helium atom have?

how many degrees of freedom do Helium atom have?

Hind

How much of NaCl is in 1.51 L of 0.300 M NaCl?

answer in moles

Cathleen

how reactive are the transition metals when compared to the group 1 metals

is it a good thing using 2 named transition metals as examples

Mimra

how reactive are transition metals compared to group 1

how reactive are transition metals compared to group 1

Stephaney

how to get pure water from salty water using household objects

how to get pure water from salty water using household objects

Gurcharan

how to make a giued about using acids and alkalis safely

iv got information about it but dont know how to lay it out

Cheryl-Ann

How will we be able to run cars when our oil supplies run out?

How can we, I just don't get it, How can we use Alcohol.

Khirea

How would soil pH change if you: a) added peat?

How would soil pH change if you: a) added peat?

Annmarie

I dont understand the photostability!!!!!!!

I was asked three questions... Describe photo stability of silver halides. Is decomposition of silver halides a redox reaction? Describe how these reactions are used in phhotography. I really dnt undastand and I am the only person in my class. I am scared to ask the teacher!!!!!!!!!!!

Somah

i need help on how to do a double reciprocal graph pleaseee

i need help on how to do a double reciprocal graph pleaseee

Rona

I need to know all the fundamentals about Alkenes and Alakanes.

I really need to know all the fundamental facts about alkanes and alkenes - I have my exams in May!!!!

Lyal

I need to write a essay on the topic below

You are to write an argumentative essay on Which Element do you think is the best/most useful one on the periodic table? Your reasons and claims should be supported by evidence. You cannot make a claim/ reason/ statement without proper evidence to support it. You will pick an element and compare and contrast it to 3 other elements. You will have to do research on your elements and counter elements, do determine your points and counter points. You also need to think of the negatives/ cons to each reason/ statement .. meaning the other point of view. You need to address the counter points/ other points of view, with evidence, and then explain why your element is better one. It is critical that when your paper is read, your element is support beyond a shadow of a doubt.

Mary-Elizabeth

If the diffusivity is observed to double when the temperature is increased by 10 degrees C, what is

If the diffusivity is observed to double when the temperature is increased by 10 degrees C, what is

Brook

Imagine you want to investigate the ideas of Priestley and Lavoisier. Assume you have been given th

You would also have access to all the usual laboratory equipment. In your plan you must give: • the one factor you would change as you carry out your investigation (the independent variable); • one factor you would observe or measure to collect your results (the dependent variable); • one of the factors you would keep the same as you carry out your investigation; • the evidence that would support Lavoisier’s idea.

Rhowan

In which type of environment does 'expansion and contraction' weathering mainly occur?

In which type of environment does 'expansion and contraction' weathering mainly occur?

Tynille

increasing atomic number and reactions with oxygen and chlorine trends.

what is the trend associated by increasing atomic number and reaction with chlorine and oxygen?

Ruaraidh

Ionic Nomenclature

Can you explain the process of changing nomenclature formulas? Also, I have a hard time understanding a lot of the polyatomic ions and the rules if the suffix is -ide, -ate, or -ite.

Uwais

Is lemonade an acid or an alkali?

Is lemonade an acid or an alkali?

Daran

is there any tutor experienced in IB chemistry HL

Chemistry HL for IB

Dugald

looking for chemistry tutor at senior freshmen level .coordination chemistry , molecular orbital

theory , thermodynamic . can start this evening , thanks

Reta

Masses and Moles

How do I work out Masses and Moles.

Nada

Measured Average

The following density measurements were made on a bar of iron: 7.58 g/mL, 8.02 g/mL, 7.83 g/mL, 7.80 g/mL, and 7.66 g/mL. The accepted value for iron's density is 7.85 g/ML. Find:

1) The average of this set of measurements 2) The average deviation of the set? 3) The relative average expressed as a percent?

For question 1 I got 7.778. For question 2 I got .126. I have no idea if these are right, and how to find the answer to number 3. Please explain your answers. Thank you!

Kasam

moles

Assuming 65 % of a human body is water (H2O) and the rest is mostly carbon (C), estimate the number of atoms in a human body

Pheona

My Project

hello, I am currently designing a machine that will basically replicate the alternator in a car but for electric cars, however I am currently stuck as I need a compound/element that is a liquid at room temperature and has a low boiling point but it also has to not react with copper. thanks.

Caleb

NH (g)+2X (g)=N (g)+4HX(g)

At a pressure of 1 atmosphere and a temperature of 25 °C, 500 cm3 of the gas HX has a mass of 0.400 g. Calculate the value of the relative atomic mass of X and hence identify element X. (You should assume that 1 mole of gas occupies 24.5 dm3, and 1 dm3 = 1000 cm3. Assume the relative atomic mass of hydrogen to be 1.0.)

Corinna

Nitrates are not tested forming a precipitate. Why not?

Nitrates are not tested forming a precipitate. Why not?

Eirlys

- ocr unit 2 - chains/energy/resources

Need to go from grade D to B ...any one that can help?

Khalil

Organic chemistry

If anyone could give me a general idea of how to solve these problems, thank you! 1. Write the chemical reaction for the formation of the respective Grignard reagents from the reaction of magnesium with the following organic halides:

(a) iodomethane (b) bromobenzene (c) chlorocyclohexane

Dustin

Particle theory of matter

i need help thinking of two higher order thinking questions about particle theory of matter and types of matter

Mykle

percentage yeild

4.00g of lawn sand (a mixture of sand and ammonium sulphate) was weighed into a conical flask, and 25 cm3 of 2.0 mol dm-3 sodium hydroxide solution was pipetted into the same flask. The conical flask was boiled for 20 minutes, after which time all the ammonia had been driven off, because: (NH4) 2SO4 (s) + 2NaOH (aq) 2NH3 (g) + Na2SO4 (aq) + 2H2O (1) The residue in the flask was cooled and filtered to remove the sand. The filtrate containing unreacted NaOH was made up to 250 cm3 in a volumetric flask. 25 cm3 samples of this solution were titrated against 0.1 mol dm-3 hydrochloric acid using bromothymol blue as an indicator. HCl + NaOH  NaCl + H2O The mean titre was 20.0 cm3. Calculate the percentage of ammonium sulphate by mass in the lawn sand.

Taylor

Polytetrafluoroethene

What does tetrafluoroethene contain that allows it to form a polymer?

Wahida

Predict the major product

(6, 3c1) The bromide 13 can be transformed to cyclic compounds in the following reaction. Predict the major product 14 and briefly give your reasoning on how you arrive at your answer.

Vincent

Project Need Help

Chemistry Investigatory Projects Experiments. (Analysis, Tests,Titration). Please suggest. i am in class 11

Susannah-Jane

reaction

copper 2 carbonate + hot dilute sulfuric acid will give what

Lucia

show that calcium carbonate is stable at room temperature?what does this mean and how do i show it

show that calcium carbonate is stable at room temperature?what does this mean and how do i show it

Katrina

Simple and fractional distillation help

I have to regulate the boiling rate, take temperature readings and measure the volume distilled. Where do I start?

Garrie

Someone explain ions to me!

I dont get all the positive and negative ions thing in chemistry!

Abd

The element zinc

If Zinc was designed to have an atomic mass of 100.0amu, what would the atomic mass of Si be?

Shabina

Urine sample in kidneys

Why is it important to look at protein over 24 hours?

Hannah

Use the periodic table to help you..

Use a periodic table to help you..? Element A has a relative atomic mass of 4 Element B has a relative atomic mass 3 times that of element A Element C has a relative atomic mass 4 times that of element A

Element A is .............. Element B is .............. Element C is ..............

What are the relative formula masses of the following?

water potassium hydroxide nitric acid sulfuric acid ammonium nitrate

Byam

Uses of Carbon Dioxide

What are 2 uses of carbon dioxide

Atholl

water that has been heated to a gas? 10 letters

school cross word

Grigor

What are covelant and Ionic Bonds

What are covelant and Ionic Bonds

Quintin

What are the common laboratory acids and alkalis?

I need their formulas too, if possible!

Ashfaq

What are the names of the salts produced by hydrochorlic acid?

What are the names of the salts produced by hydrochorlic acid?

Sonia

what can you talk about if you find anomailes result in your graph

for controlled assesment

Ozma

What colour change would you observe during this reaction?

CuCO3 + H2SO4 --> CuSO4 + H20 + CO2

Hanif

what does particulates do?

what does particulates do?

Bettina

What happens to the particles in pancakes when you cook it ?

What happens to the particles in pancakes when you cook it ?

Yvanne

what is a chemical change?

what is a chemical change?

Kam

what is an addition polymer?

what is an addition polymer?

Anastasia

what is cracking

what is cracking

Ainsleigh

what is electrolysis

what is electrolysis

Clem

what is human activity

what is human activity and its causes.

Catherine

what is the bohr effect

as level question

Balwinder

What is the bond order of the diatomic molecule BN

What is the bond order of the diatomic molecule BN

Cairol

What is the chemical test for glucose?

What is the chemical test for glucose?

Ariana

What is the mass of 6.299 × 1023 atoms C? Answer in units of g

What is the mass of 6.299 × 1023 atoms C? Answer in units of g

Umezeyi

what is the scientific name for limewater?

what is the scientific name for limewater?

Jemmison

What makes an american pancake rise once its cooked?

What makes an american pancake rise once its cooked?

Lovat

what makes oxygen

what makes oxygen

Nalila

When an acid and an alkali react which two substances are always made?

When an acid and an alkali react which two substances are always made?

Furah

When you add elements how do you write the equation? URGENT!

When you add elements how do you write the equation? URGENT!

Tracey-Anne

Where can you find sulphuric acid in your home?

Where can you find sulphuric acid in your home?

Motema

Why are both Alchemy and the Phlogiston theory wrong?

For my science homework I've got to wright in my own words why alchemy and the phlogiston theory are wrong, but I'm not sure as to why they are. Can someone help me??

Leandra

Why are d-block elements not as reactive as s-block elements

Why are d-block elements not as reactive as s-block elements

Nils

why cant you make a hot cup of tea on high ground

why cant you make a hot cup of tea on high ground

Ruhina

why is calcium oxide more hazardous than calcium hydroxide?

why is calcium oxide more hazardous than calcium hydroxide?

Solvi

Why use copper instead of copper carbonate to prepare copper sulphate using sulfuric acid

I want to prepare copper sulphate using sulfuric acid. I have a sample of copper metal and a sample of copper carbonate. If I'm to use one of the materials which should it be and why

Sanjeev

/write and balance three euations that have the abulity to produce hydrogen gas as a product

/write and balance three euations that have the abulity to produce hydrogen gas as a product

Cherlouise

Reacting Carbon Dioxide with Lime water


What happens when Lime Water reacts to Carbon Dioxide?

Carbon dioxide reacts with limewater to form calcium carbonate, which precipitates out of the solution. The carbon dioxide and limewater react to produce calcium carbonate and water. Calcium carbonate is chalk, and when it is produced, it precipitates and solid particles of chalk appear. The appearance of this solid makes the liquid appear ‘milky’. The white milky suspension/precipitate is caused by the formation of calcium carbonate. The characteristic test for CO2, is checking that the limewater is milky. This is because chalk is precipitating in the limewater. Bubbling carbon dioxide through the solution for an extended period of time makes the solution become clear and colourless. This happens as the carbon dioxide forms acidic carbonic acid when it dissolves in the water, the carbonic acid (H2CO3) reacts further with the calcium carbonate: CO2 + H2O ——> H2CO3H2CO3 +CaCO3 ——–> Ca(HCO3)2 Ca(HCO3)2 = calcium hydrogen carbonate which is soluble in water. This chemistry is important in understanding how hard water is formed and then limescale is formed in kettles and hot water boilers.

Carbon dioxide and lime water experiment What happens when you mix carbon dioxide and lime water?

Written as an Equation

In its equation form that makes: CO2 + Ca (OH)2 -----> ? CO2 + Ca(OH)2 —-> CaCO3 + H2O

Deli

How does copper oxide and sulphuric acid react to eachother?


Reacting Copper Oxide with Sulphuric Acid

Mixing copper oxide and sulphuric acid is an experiment involving an insoluble metal oxide which is reacted with a dilute acid to form a soluble salt. Copper (II) oxide, is a black solid, which, when reacted with sulphuric acid creates a cyan-blue coloured chemical called copper II sulfate. Copper (II) oxide reacts with sulfuric acid to create water and copper (II) sulfate. This reaction could be classified as a double displacement reaction or a neutralization reaction.

copper sulphate Copper sulphate takes on a bright blue colour

Writing the Equation form of  Copper oxide + Sulphuric Acid

This chemical reaction can be written as the following:

CuO +H2SO4 -> CuSO4 + H2O

Copper oxide(solid) + Sulphuric Acid (aqueous)-> Copper Sulphate (aqueous)+ Water(liquid) To find out how you can make Copper Sulphate at home check out this article.

Liusadh

How do you know whether to use 'ide' or 'ate', when naming a compound?


How are Chemical Compounds Named?

Chemical nomenclature is the process of naming compounds. Naming compounds is important to allow scientists to identify and recognise the different compounds. When naming molecular compounds prefixes are used to dictate the number of a given element present in the compound. For example:

  • “mono-” indicates one,
  • “di-” indicates two,
  • “tri-” is three,
  • “tetra-” is four,
  • “penta-” is five,
  •  “hexa-” is six,
  • “hepta-” is seven,
  • “octo-” is eight,
  • “nona-” is nine,
  • and “deca” is ten.

For a more in depth explanation check out this video.

How do you know whether to use 'ide' or 'ate', when naming a compound?

-ide is used for non-metal compounds generally. For example, Chlorine forms a chloride ion, so NaCl is Sodium Chloride. -ate and -ite are commonly used for polyatomic ions of Oxygen. -ate is used for the ion that has the largest number of Oxygen atoms. The -ite would be used for the ion with the smaller. NO2 and NO3 are known as Nitrite and Nitrate respectively. Nitrite has a smaller number of oxygen atoms so when added to an element it will be _ Nitrite. On the other than, Nitrate has a larger number of Oxygen atoms so when added to an element it is _ Nitrate Share your tips and advice for learning the names of chemical compounds in the comments.    

Inin

What is a protein molecule called?

  What is a protein molecule called?

Kerrieann

Chemistry

  Show that a conventional x-ray generator is incapable of generating x-rays of wavelength as low as 10-11m. Do this by determining the identity of the target (in atomic number, Z) which would be needed to generate such x-rays.

Morrison

chemistry

  explain how the reactivity can be demonstrate experimentally?

Caragh

chemistry

  What is the pH of 0.100 mol dm-3 ammonia solution if Ka for the ammonium ion is 5.62 x 10-10 mol dm-3? Kw = 1.00 x 10-14 mol2dm-14

Marcos

chemical structures. please help!

  Hi, can anyone tell me which bonds are in: Na3C6H5O7. For example C-O, thank you 🙂

Caitlinn

lattice enthalpy

lattice enthalpy

Charis

Ksp

Full question and my working is attached in the below.I would be glad if I could have a detailed explanation.

Oscar

  • Superprof Resources
    • Questions
    • Academic
  • About
    • Find a tutor
    • Who are we?
    • Need help?
    • Resources in French
    • Resources in Spanish
  • Follow the adventure
    • Become a Tutor