chemistry

This page lists questions and answers that were posted by visitors named chemistry.

Questions

The following questions were asked by visitors named chemistry.

what does an atom of lead look like? what are the parts that compose of the atom? help me pls

The mole fraction of acetic acid (CH3COOH) in an aqueous solution is 0.675. Calculate the molarity of the acetic acid, if the density of the solution is 1.0266 g mL-1. To give a different take on this, here is another way of approaching the problem. I don...

I understand that polymers are long chain 500-20,000 repeating units, but I don't know: what car components are made of polymers?

how does cross linking alter the properties of a polymer?

a gaseous hydrocarbon reacts completely with oxygen gas to form carbon dioxide and water vapor. given the following data, determine (delta)HoF for hydrocarbon: (delta)Horxn=-2044.5kj/mol hydrocarbon (delta)HoF CO2= -393.5kj/mol (delta)HoF H2O = -242kj/mol...

What is the difference between Keq and the term of [prod]pr / [react]pr?

CH3 CH3-C-CH3 CH3CH2CH2-C-CH2CH2CH2CH3 CH3 give the IUPAc name for this compound? is it 4-methyl-4-tert-methyloctane?

calculate [H+] if [OH] is 1.688x10^-3

The free energy change for dissolution of CaSO4 at 25C is 28.774kJ/mole. What is the solubility of this compound. i got ksp lnK = deltaG/RT lnK= 28774/(-8.31*298) Ksp = 2.39e-12 i don't know waht to do after this..

what did i do wrong? i need to find lowest vapor pressure. a 0.13 m FeCl3 b 0.50 m sucrose c 0.24 m NaNO3 d 0.15 m Na2PO4 so i solved. a 4 x 0.13 = 0.52 b 1 x 0.50 = 0.50 c 5 x 0.24 = 1.2 d 7 x 0.15 = 1.05 i chose C but the answer is A. did i do something...

Given the reaction 3C(s) + 4H2(g) + 5O2(g) ---> 3CO2(g) + 4H2O(l) ÄH= -2323.7 kJ How much heat would be released when 34.1 g of H2 react?

What is the lattice energy of NaBr? heat of formation of NaBr = -362 kJ/mol heat of sublimation for Na = 107.30 kJ/mol ionization energy for Na = 496 kJ/mol bond dissociation energy for Br2 = 190 kJ/mol electron affinity of Br = -325 kJ/mol heat of vapori...

Consider the hypothetical elements X and Y. Suppose the enthalpy of formation for the compound XY is ƒ{336 kJ/mol, the bond energy for X2 is 414 kJ/mol, and the bond energy for Y2 is 159 kJ/mol. Estimate the XY bond energy in units of kJ/mol.

An ionic compound has the following composition (by mass): Mg, 10.9%; Cl, 31.8%; O, 57.3%. What is the formula and name of this compound?

A gaseous compound has the following composition by mass: C, 25.0%; H, 2.1%; F, 39.6%; O, 33.3%. Its molecular weight is 48 g/mol

A molecular compound is composed of 58.8% Xe, 7.2% O, and 34.0% F, by mass. If the molecular weight is 223 g/mol, what is the molecular formula? Draw the correct Lewis structure. Predict the molecular geometry using the VSEPR model.

Excess fluorine, F2(g), reacts at 150°C with bromine, Br2(g), to give a compound BrFn. If 423 mL Br2(g) at 150°C and 748 mmHg produced 4.20 g BrFn, what is n? Predict the shape of this molecule using the VSEPR model.

the teacher instructed three students A,B,and C respectively to prepare a 50% (mass by volume) solution of sodium hydroxide (NaOH). 'A' dissolved 50 g of NaOH in 100 ml of water B dissolved 50g of NaOH in 100g of water while C dissolved 50g of NaOH in wat...

why is it that when an unknown carbonate of group one or two (inc H) reacting w/ HCl, the mole ratio is 1:1

out of the pairs of orbitals which has a higher amount of energy 4f or 6s

what are some good compounds(salts, acids,/bases) that are good conductors when dissolved in h2o

how to identify bond angles

Alexandra decides to climb Mt. Krumpett, which is 5000 high. She determines that this will require a total of 3600 of energy for the trip. For her food supply, she decides to take nutrition bars. The label states that each bar contains 50 of carbohydrates...

How will you prepare potassium per magnate.

write raction of benzoic acid with propylamine

1. lactate has a molecular weight of 90.08. How much lactate is needed to make 3 liters of .15 molar lactate. 2.What is the percentage of lactate (it's a solid) in the solution made in question 1.

A sample of toluene, C7H8 has a mass of 74.5 g. a) how many molecules does the sample contain? b) How many carbon atoms does it contain? How many hydrogen atoms does it contain? My work For b would it be 7 carbon atoms and 8 hydrogen atoms

A solution contains 2.0 × 10^–3 M Ba^2+ and 1.0 × 10^–2 M Sc^3+. A source of F^– is slowly added to the solution. Will BaF2 (Ksp = 1.84 × 10^–7) or ScF3 (Ksp = 5.81 × 10^–24) precipitate first? I believe that ScF3 would precipitate first but I don't know...

what is a solubility rate?

How match water make in 0.123 N NaoH for 0.1 N NaoH

what is the source of activation energy in an exothermic reaction? Is an example heat?

1:when 20.0ml of 1.7m AgN03 added to grammar of AgCL will be produced? 2:if the percentage yield is 30%,calculate the actual yield.

ammonia is produced from the reaction of nitrogen and hydrogen according to the following balanced equation. N2+3H2g----- > 2NH3g. what is the maximum mass that can be produced from a mixture of 2.00×10³gN and 8.00×10⁴H2?

How much heat is required to take 4 kg of water from 20◦C to near boiling at 99◦C? Answer in units of J. I got 1320.88?

what would be the e configuration for sodium- 23 (up and down arrows) 1s- ? arrows 2s- ? arrows 2p- ? arrows 3s- ? arrows 3p- ? arrows

write a balanced equation for the reaction : if 40cm3 of Carbon (2) oxide were mixed with 30cm3 of oxygen : calculate the volume of Carbon(4) oxide gas produced

MnO4–(aq) + Cl–(aq) MnO2(s) + Cl2(g) (unbalanced) i. Balance the given half-reactions for atoms and charge. (0.5 points) MnO4– + H2O MnO2 + OH– Cl– Cl2 ii. Multiply to balance the charges in the reaction. (0.5 points) iii. Add the equations and simplify t...

Answers

The following answers were posted by visitors named chemistry.

Thank you DrBob222! I got it now!

i get how you get X = 2.077*Y, but i don't understand how if you plug in 0.481X in for Y to solve for x. x = 2.077(0.481x) x = 0.999x then what??? i know this is probably a simple stupid math question, but i need to do another problem like this and i'm st...

how can you fill a flask with pure oxygen without mixing it with air

discuss the kinetic theory of gases and proof that the equation pv =1/3 mv2

thanks for the help but im still not getting the right answer

im getting 1.54e-6

9904.7 is the answer but I already tried that and its not working

it worked now, thank you!

7z + 5 = 21 7z=21-5 7z=16 z=16/7

factor out 5 u get 5(4x^2+8x +3) = 0 5(4x^2+2x+6x+3)=0 5(2x(2x+1)+3(2x+1))=0 5(2x+1)(2x+3)=0 x=-1/2 or x=-3/2

randy re check the question and use brackets to identify do u mean secant squared? or secant to the power of 2x-1

-3,-2,4 use the number line

6y+-4x + y -x 7y -5x

re write the question properly sec^2 x? is there something there? there should be either x or thetha there and is it multplied

Not just Na I mean all group 1 and 2 elements

any more other than these that can be easily accessed

where can I access this? and are they all good conductors

could i use it safely at home

thx but wat is a good way to remember it

So would i multiply 4.86 x 10^23 by 7 to get the number of carbon atoms And multiply by 8 to get the number of hydrogen atoms

A. 8.75a + 6.5c + 6.5s = total cost. B. 8.75(2) + 6.5(3) + 6.5(4) = answer C. 8.75(4) + 6.5(2) = answer Just compare the totals to see if they are the same

CH4 is the limiting reactant

4.18 x 4kg x (99-20)

I put this answer into my homework and got it wrong

A is a solution of trioxonitrate (v)acid, HNO3 of unknown concentration.B is standard solution of sodium hydroxide containing 4.00g per dm3 of solution. 25 cm3 portion solution B required an average of 24.00cm3 of solution A for neutralization using 2drop...

what is the volume of oxygen at s t p will be obtained when 24.5g of potassium trioxochlorite