# DrBob222

posted by .

Consider the following reaction at 298 K:
C(graphite) +2Cl2 (g) -----> CCl4(l)

Calculate the following quantities.

Delta H: -139 kJ/mol

deltaS(sys)=? J/mol*K
deltaS(surr)=? J/mol*K
deltaS(univ)=? J/mol*K

deltaS(sys)=654.9J/mol*K
deltaS(surr)=0.4664 J/mol*K
deltaS(univ)=655.366J/mol*K

Is this right???????????
chemistry - DrBob222, Wednesday, March 14, 2012 at 11:20pm
Your tables may not be the same as mine but I looked and found
Cl2 for Cl2 = 223.0 J/mol
C(graphite) = 5.740
CCl4(l) = 216.4
If I use S products - S reactants that becomes 216.4 - 5.740 - (2*223.0) and I don't see anything in your answers close to that.

chemistry - Kelsey, Wednesday, March 14, 2012 at 11:41pm
So what are the answers for
deltaS(sys)=? J/mol*K
deltaS(surr)=? J/mol*K
deltaS(univ)=? J/mol*K
I need to verify the correct answers. Could you please tell me...Thanks!

chemistry - Kelsey, Wednesday, March 14, 2012 at 11:44pm
Also I don't know how you are working this problem out.

chemistry - Kelsey, Thursday, March 15, 2012 at 12:34am

• DrBob222 -

chemistry - Kelsey, Thursday, March 15, 2012 at 1:16am
deltaS(sys)=654900J/mol*K
deltaS(surr)=466.4 J/mol*K
deltaS(univ)=655366J/mol*K

Sorry I forgot to convert to J

• DrBob222 -

• DrBob222 -

I have dS for system =
216.4 - 5.74 -2(223.0) = ? J/mol = -235.3 J/mol Check that.

dS for surroundings = -dH/T = -(-139,000)/298 = 466.4 J/mol

dS total (universe) = dS sys + dS surr = -235.3J + 466.4 = ? check that.
Check the signs. Check the # s.f.

• DrBob222 -

Everything is right except the system...i put -253.5 and it marked me wrong :(

• DrBob222 -

I think u added wrong on accident

• DrBob222 -

Wait never mind that's what i got as the answer....so why is it wrong?

• DrBob222 -

The best advice I have is for you to verify those numbers from your text/notes. I took these from a text that is almost 20 years old; newer numbers may be in your text. That's what meant with my first post; I gave you the numbers I had and I hoped you would check them with your reference.
I am puzzled too. If the dS univ is ok and the dS surroundings is ok, how can the dS system be out of whack since dS univ = dS sys + dS surr

• DrBob222 -

the answer is -235.5...you subtracted wrong! Thanks for the help :)

## Similar Questions

1. ### AP Chemisty

N2(g)+3F2 yields 2Nf3(g) Delta H(degree)298=-264KJ mol-1;Delta S(degree)298=-278J K-1 mol-1 The following questions relate to the synthesis reaction represented by the chemical equation above. a.)CAlculate the value of the standard …
2. ### chemistry

Given the following data at 298K, calculate delta S for : 2Ag2O(s) -> 4Ag(s) +O2(g) deltaS(J/mol.K)121.3 42.6 205.2
3. ### Chemistry

For the reaction described by the chemical equation: 3C2H2(g) -> C6H6(l) .. Delta H rxn = -633.1 kJ/mol a) Calculate the value of Delta S rxn at 25.0 C... b) Calculate Delta G rxn... c) In which direction is the reaction, as written, …
4. ### chemistry

Consider the following reaction at 298 K: C(graphite) +2Cl2 (g) -----> CCl4(l) Calculate the following quantities. Delta H: -139 kJ/mol deltaS(sys)=?
5. ### chemistry

Consider the following reaction at 298 K: C(graphite) +2Cl2 (g) -----> CCl4(l) Calculate the following quantities. Delta H: -139 kJ/mol deltaS(sys)=?

I posted this question already but you never replied back :( Consider the following reaction at 298 K: C(graphite) +2Cl2 (g) -----> CCl4(l) Calculate the following quantities. Delta H: -139 kJ/mol deltaS(sys)=?
7. ### chemistry

In which case will the equilibrium constant (K) be less than 1 at 298 K?
8. ### Chemistry

Determine the entropy change when 1.80 mol of HBr(g) condenses at atmospheric pressure?
9. ### Chemistry

Determine ∆G° (in kcal) for the reaction CCl4(ℓ) + H2(g) HCl(g) + CHCl3(ℓ) at 25 °C under standard conditions. The following information is available: At 25 °C C(graphite) + 2Cl2(g) CCl4(ℓ) ∆S° = -56.23 …
10. ### AP Chemistry

Calculate the delta H rxn for the following reaction: CH4(g)+4Cl2(g)-->CCl4(g)+4HCl Use the following reactions and given delta H's: 1) C(s)+2H2(g)-->CH4(g) delta H= -74.6 kJ 2) C(s)+2Cl2(g)-->CCl4(g) delta H= -95.7 kJ 3) …

More Similar Questions