Question

1)The value of Hº for the decomposition of calcium chloride into its constituent elements, CaCl2 (s) Ca (s) + C12 (8) is_ A) +795.8 B) 0.00 C) -795.8 D) +397.9 E) -3979 kJ/mol. 2)The value of Gºat 25 °C for the decomposition of gaseous sulfur trioxide to solid elemental sulfur and gaseous oxygen, 2503 (g) 28 (s, rhombic) + 302 (g) is_ kJ/mol. A) -740.8 B)-370.4 C) +740.8 D) +370.4 E) +185.2 3)The value of Gºat 25 °C for the formation of POC13 from its constituent elements, P2(g) + O2(g) + 3C12(g) 2POC13 () is kJ/mol. A) -1,005 B)-1108.7 C)-606.2 D) +1108.7 E) +606.2 4)The value of Gº at 161.0 °C for the formation of calcium chloride from calcium metal and chlorine gas is _kJ/mol. At 25.0 °C for this reaction. Hºis -795.8 kJ/mol, Gº is -748.1 kJ/mol, and Sis -1598 JK. A) -726.4 B) -770.1 C) 2.49 104 D) -865.2 E) 6.86 x 104 k J/mol. 5) For a given reaction with S = -58.4 J/K-mol, the G=0 at 364 K. The value of H must be assuming that H and S do not vary with temperature. A) 1.60 x 10-4 B) -1.60 x 10-4C) -21.3 D) 21.3 E)-6.23 x 10-3 k J/mol, assuming that H and S do 6) For a given reaction with S = 50.8 J/K-mol, the G = 0 at 395 K. The value of H must be not vary with temperature. A) -20.1 B) -7.78 x 10-3 C) -1.29 x 10-4D) 20.1 E) 1.29 x 10-4

Everything is correct now... Can you please help me out with these?

Answer 1

1)ANSWER OPTION A

CaCl2$\rightarrow$Ca+Cl2

$\Delta$H0 =$\sum$$\Delta$H0 (pdt) - $\sum$ $\Delta$H0 (rea)

std enthalpy values are

CaCl2= -795.8kj/mol

Ca=0

Cl2=0

$\Delta$H0 =[(0KJ/MOL) -(-795.8KJ/MOL) =795.8KJ/MOL

2)OPTION C IS CORRECT

2SO3$\rightarrow$2S+3O2

$\Delta$G0 =$\sum$G0 (pdt) - $\sum$ G0 (rea)

std G0 values are

SO3= -371KJ/MOL

S=0

O2=0

$\Delta$G0 =[(0KJ/MOL) - (2*-371KJ/MOL)]= 742KJ/MOL

3)OPTION B IS CORRECT

P2+O2+3Cl2$\rightarrow$2POCl3

P2=103.8KJ/MOL

O2=0

Cl2=0

POCl3= - 502.5kj/mol

$\Delta$G0 =[(2* -502.5KJ/MOL) -( 103.8KJ/MOL)]= -1108.8

4)OPTION 1 IS CORRECT

$\Delta$G0 =$\Delta$H0 - T$\Delta$S0

Given H0 = -795.8KJ/MOL

S0 = -159.8J/K= -0.1598kj/K

T=161.00 C=434K

$\Delta$G0 = (-795.KJ/MOL) -(434K* -0.1598KJ/MOL.K)=-726.45KJ/MOL