From the following reactions at 298 K,CaC 2(s)+ 2 H 2 O (l) longrightarrow Ca ( OH )2(s) + C 2 H 2(g) DH °( kJ mol -1)-127.9 (B) Ca (s)+(1/2) O 2(g) longrightarrow CaO (s)-635.1 (C) CaO ( s )+ H 2 O (I) longrightarrow Ca ( OH )2(s)-65.2 (D) C ( s )+ O 2( s ) longrightarrow CO 2(s)-393.5 (E) C 2 H 2(g)+(5/2) O 2(g) longrightarrow 2 CO 2(g)+ H 2 O (e)-1299.58 Calculate the heat of formation of CaC 2(s) at 298 K.

Question

From the following reactions at 298 K,CaC 2(s)+ 2 H 2 O (l) longrightarrow Ca ( OH )2(s) + C 2 H 2(g) DH °( kJ mol -1)-127.9 (B) Ca (s)+(1/2) O 2(g) longrightarrow CaO (s)-635.1 (C) CaO ( s )+ H 2 O (I) longrightarrow Ca ( OH )2(s)-65.2 (D) C ( s )+ O 2( s ) longrightarrow CO 2(s)-393.5 (E) C 2 H 2(g)+(5/2) O 2(g) longrightarrow 2 CO 2(g)+ H 2 O (e)-1299.58 Calculate the heat of formation of CaC 2(s) at 298 K. (A) -59.82 KJ mol -1 (B) +59.82 KJ mol -1 (C) -190.22 KJ mol -1 (D) +190.22 KJ mol -1

Tardigrade Admin · Accepted Answer

We have to calculate Δ Ho for the following reaction in which one mole of C a C2(S) is formed form its elements. Ca (S)+2 C(S) arrow C a C2(S) This is obtained when we operate. (B)+(C)+z(D)-(E)-a ∴ Δ H=(-635.1)+(-65.2)+2(-393.5) -(-1299.58)-(-127.9) kJ m o l-1 =-59.82 kJ mol -1

$- 59.82 K J m o l^{- 1}$

$+ 59.82 K J m o l^{- 1}$

$- 190.22 K J m o l^{- 1}$

$+ 190.22 K J m o l^{- 1}$

−59.82KJmol−1

+59.82KJmol−1

−190.22KJmol−1

+190.22KJmol−1

We have to calculate ΔHo for the following reaction in which one mole of CaC2​(S) is formed form its elements. Ca(S)+2C(S)→CaC2​(S) This is obtained when we operate. (B)+(C)+z(D)−(E)−a ∴ΔH=(−635.1)+(−65.2)+2(−393.5) −(−1299.58)−(−127.9)kJmol−1 =−59.82kJmol−1

$- 59.82 K J m o l^{- 1}$

$+ 59.82 K J m o l^{- 1}$

$- 190.22 K J m o l^{- 1}$

$+ 190.22 K J m o l^{- 1}$