the species which by definition has zero standard molar

The species which by definition has zero standard molar enthalpy of formation at $$298\,K$$ is

A. $$B{r_2}\left( g \right)$$

B. $$C{l_2}\left( g \right)$$

C. $${H_2}O\left( g \right)$$

D. $$C{H_4}\left( g \right)$$

Answer : $$C{l_2}\left( g \right)$$

Solution :
The species in its elemental form has zero standard molar enthalpy of formation at $$298\,K.$$ At $$298\,K,C{l_2}$$ is gas while $$B{r_2}$$ is liquid.

Releted MCQ Question on
Physical Chemistry >> Chemical Thermodynamics

Releted Question 1

The difference between heats of reaction at constant pressure and constant volume for the reaction : $$2{C_6}{H_6}\left( l \right) + 15{O_{2\left( g \right)}} \to $$ $$12C{O_2}\left( g \right) + 6{H_2}O\left( l \right)$$ at $${25^ \circ }C$$ in $$kJ$$ is

A. $$-$$ 7.43

B. $$+$$ 3.72

C. $$-$$ 3.72

D. $$+$$ 7.43

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Releted Question 2

For which change $$\Delta H \ne \Delta E\,:$$

A. $${H_{2\left( g \right)}} + {I_{2\left( g \right)}} \to 2HI\left( g \right)$$

B. $$HC{\text{l}} + NaOH \to NaC{\text{l}}$$

C. $${C_{\left( s \right)}} + {O_{{2_{\left( g \right)}}}} \to C{o_{{2_{\left( g \right)}}}}$$

D. $${N_2}\left( g \right) + 3{H_2}\left( g \right) \to 2N{H_3}\left( g \right)$$

View Answer

Releted Question 3

$${\text{The}}\,\Delta H_f^0\,{\text{for}}\,C{O_2}\left( g \right),\,CO\left( g \right)\,$$ and $${H_2}O\left( g \right)$$ are $$-393.5,$$ $$-110.5$$ and $$ - 241.8\,kJ\,mo{l^{ - 1}}$$ respectively. The standard enthalpy change ( in $$kJ$$ ) for the reaction $$C{O_2}\left( g \right) + {H_2}\left( g \right) \to CO\left( g \right) + {H_2}O\left( g \right)\,{\text{is}}$$

A. 524.1

B. 41.2

C. -262.5

D. -41.2

View Answer

Releted Question 4

In thermodynamics, a process is called reversible when

A. surroundings and system change into each other.

B. there is no boundary between system and surroundings.

C. the surroundings are always in equilibrium with the system.

D. the system changes into the surroundings spontaneously.

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The species which by definition has zero standard molar enthalpy of formation at $$298\,K$$ is

Releted MCQ Question on
Physical Chemistry >> Chemical Thermodynamics

The difference between heats of reaction at constant pressure and constant volume for the reaction : $$2{C_6}{H_6}\left( l \right) + 15{O_{2\left( g \right)}} \to $$ $$12C{O_2}\left( g \right) + 6{H_2}O\left( l \right)$$ at $${25^ \circ }C$$ in $$kJ$$ is

For which change $$\Delta H \ne \Delta E\,:$$

In thermodynamics, a process is called reversible when

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Chemical Thermodynamics

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The species which by definition has zero standard molar enthalpy of formation at $$298\,K$$ is

Releted MCQ Question on Physical Chemistry >> Chemical Thermodynamics

The difference between heats of reaction at constant pressure and constant volume for the reaction : $$2{C_6}{H_6}\left( l \right) + 15{O_{2\left( g \right)}} \to $$ $$12C{O_2}\left( g \right) + 6{H_2}O\left( l \right)$$ at $${25^ \circ }C$$ in $$kJ$$ is

For which change $$\Delta H \ne \Delta E\,:$$

In thermodynamics, a process is called reversible when

Practice More Releted MCQ Question on Chemical Thermodynamics

Practice More MCQ Question on Chemistry Section

Releted MCQ Question on
Physical Chemistry >> Chemical Thermodynamics

Practice More Releted MCQ Question on
Chemical Thermodynamics