272736
For the gas phase reaction, $\mathrm{PCl}_5(\mathrm{~g}) \square \mathrm{PCl}_3(\mathrm{~g})+\mathrm{Cl}_2(\mathrm{~g})$ Which of the following condition are correct?
1 $\Delta \mathrm{H}<0$ and $\Delta \mathrm{S}<0$
2 $\Delta \mathrm{H}>0$ and $\Delta \mathrm{S}<0$
3 $\Delta \mathrm{H}=0$ and $\Delta \mathrm{S}<0$
4 $\Delta \mathrm{H}>0$ and $\Delta \mathrm{S}>0$
Explanation:
$\mathrm{PCl}_5(\mathrm{~g}) \square \quad \mathrm{PCl}_3(\mathrm{~g})+\mathrm{Cl}_2$ (g) One mole of $\mathrm{PCl}_5$ is dissociated into two moles of $\mathrm{PCl}_3$ and $\mathrm{Cl}_2$ in the same phase hence, the process is endothermic i.e., $\Delta \mathrm{H}>0$. Also $\Delta \mathrm{S}>0$ as one mole of gaseous reactant gives two moles of gaseous products and randomness increases.
COMEDK-2018
Thermodynamics
272737
A piece of ice kept at room temperature melts of its own. This reaction is governed by which law?
1 Zeroth law of Thermodynamics
2 Third law of Thermodynamics
3 First law of Thermodynamics
4 Second law of Thermodynamics
Explanation:
When ice changes into water spontaneously at room temperature, the randomness increases, so entropy increases which is in accordance with the second law of thermodynamics. - The zeroth law of thermodynamics states that if two bodies are each in thermal equilibrium with some third body, then they are also in equilibrium with each other. - The third law of thermodynamics state that the entropy of a system become constant at absolute zero temperature.
GUJCET-2008
Thermodynamics
272738
Which of the following is not an intensive property?
1 Entropy
2 Melting point
3 Specific gravity
4 Refractive index
Explanation:
Intensive property - An intensive property is one that does not depend on the mass of the substance or system. Example- Temperature, pressure, density etc. Extensive property - An extensive property is a property that depends on the amount of matter or mass in a sample. Example- Enthalpy, entropy, internal energy etc.
Shift-I
Thermodynamics
272765
The second law of thermodynamics says that in a cyclic process
1 work cannot be converted into heat
2 heat cannot be converted into work
3 work cannot be completely converted into heat
4 heat cannot be completely converted into work
Explanation:
According to second law of thermodynamics- - No cyclic process that converts heat entirely into work is possible. - Work can never be equal to $Q$. - Some energy must always be transferred as heat to the system's surrounding.
272736
For the gas phase reaction, $\mathrm{PCl}_5(\mathrm{~g}) \square \mathrm{PCl}_3(\mathrm{~g})+\mathrm{Cl}_2(\mathrm{~g})$ Which of the following condition are correct?
1 $\Delta \mathrm{H}<0$ and $\Delta \mathrm{S}<0$
2 $\Delta \mathrm{H}>0$ and $\Delta \mathrm{S}<0$
3 $\Delta \mathrm{H}=0$ and $\Delta \mathrm{S}<0$
4 $\Delta \mathrm{H}>0$ and $\Delta \mathrm{S}>0$
Explanation:
$\mathrm{PCl}_5(\mathrm{~g}) \square \quad \mathrm{PCl}_3(\mathrm{~g})+\mathrm{Cl}_2$ (g) One mole of $\mathrm{PCl}_5$ is dissociated into two moles of $\mathrm{PCl}_3$ and $\mathrm{Cl}_2$ in the same phase hence, the process is endothermic i.e., $\Delta \mathrm{H}>0$. Also $\Delta \mathrm{S}>0$ as one mole of gaseous reactant gives two moles of gaseous products and randomness increases.
COMEDK-2018
Thermodynamics
272737
A piece of ice kept at room temperature melts of its own. This reaction is governed by which law?
1 Zeroth law of Thermodynamics
2 Third law of Thermodynamics
3 First law of Thermodynamics
4 Second law of Thermodynamics
Explanation:
When ice changes into water spontaneously at room temperature, the randomness increases, so entropy increases which is in accordance with the second law of thermodynamics. - The zeroth law of thermodynamics states that if two bodies are each in thermal equilibrium with some third body, then they are also in equilibrium with each other. - The third law of thermodynamics state that the entropy of a system become constant at absolute zero temperature.
GUJCET-2008
Thermodynamics
272738
Which of the following is not an intensive property?
1 Entropy
2 Melting point
3 Specific gravity
4 Refractive index
Explanation:
Intensive property - An intensive property is one that does not depend on the mass of the substance or system. Example- Temperature, pressure, density etc. Extensive property - An extensive property is a property that depends on the amount of matter or mass in a sample. Example- Enthalpy, entropy, internal energy etc.
Shift-I
Thermodynamics
272765
The second law of thermodynamics says that in a cyclic process
1 work cannot be converted into heat
2 heat cannot be converted into work
3 work cannot be completely converted into heat
4 heat cannot be completely converted into work
Explanation:
According to second law of thermodynamics- - No cyclic process that converts heat entirely into work is possible. - Work can never be equal to $Q$. - Some energy must always be transferred as heat to the system's surrounding.
272736
For the gas phase reaction, $\mathrm{PCl}_5(\mathrm{~g}) \square \mathrm{PCl}_3(\mathrm{~g})+\mathrm{Cl}_2(\mathrm{~g})$ Which of the following condition are correct?
1 $\Delta \mathrm{H}<0$ and $\Delta \mathrm{S}<0$
2 $\Delta \mathrm{H}>0$ and $\Delta \mathrm{S}<0$
3 $\Delta \mathrm{H}=0$ and $\Delta \mathrm{S}<0$
4 $\Delta \mathrm{H}>0$ and $\Delta \mathrm{S}>0$
Explanation:
$\mathrm{PCl}_5(\mathrm{~g}) \square \quad \mathrm{PCl}_3(\mathrm{~g})+\mathrm{Cl}_2$ (g) One mole of $\mathrm{PCl}_5$ is dissociated into two moles of $\mathrm{PCl}_3$ and $\mathrm{Cl}_2$ in the same phase hence, the process is endothermic i.e., $\Delta \mathrm{H}>0$. Also $\Delta \mathrm{S}>0$ as one mole of gaseous reactant gives two moles of gaseous products and randomness increases.
COMEDK-2018
Thermodynamics
272737
A piece of ice kept at room temperature melts of its own. This reaction is governed by which law?
1 Zeroth law of Thermodynamics
2 Third law of Thermodynamics
3 First law of Thermodynamics
4 Second law of Thermodynamics
Explanation:
When ice changes into water spontaneously at room temperature, the randomness increases, so entropy increases which is in accordance with the second law of thermodynamics. - The zeroth law of thermodynamics states that if two bodies are each in thermal equilibrium with some third body, then they are also in equilibrium with each other. - The third law of thermodynamics state that the entropy of a system become constant at absolute zero temperature.
GUJCET-2008
Thermodynamics
272738
Which of the following is not an intensive property?
1 Entropy
2 Melting point
3 Specific gravity
4 Refractive index
Explanation:
Intensive property - An intensive property is one that does not depend on the mass of the substance or system. Example- Temperature, pressure, density etc. Extensive property - An extensive property is a property that depends on the amount of matter or mass in a sample. Example- Enthalpy, entropy, internal energy etc.
Shift-I
Thermodynamics
272765
The second law of thermodynamics says that in a cyclic process
1 work cannot be converted into heat
2 heat cannot be converted into work
3 work cannot be completely converted into heat
4 heat cannot be completely converted into work
Explanation:
According to second law of thermodynamics- - No cyclic process that converts heat entirely into work is possible. - Work can never be equal to $Q$. - Some energy must always be transferred as heat to the system's surrounding.
272736
For the gas phase reaction, $\mathrm{PCl}_5(\mathrm{~g}) \square \mathrm{PCl}_3(\mathrm{~g})+\mathrm{Cl}_2(\mathrm{~g})$ Which of the following condition are correct?
1 $\Delta \mathrm{H}<0$ and $\Delta \mathrm{S}<0$
2 $\Delta \mathrm{H}>0$ and $\Delta \mathrm{S}<0$
3 $\Delta \mathrm{H}=0$ and $\Delta \mathrm{S}<0$
4 $\Delta \mathrm{H}>0$ and $\Delta \mathrm{S}>0$
Explanation:
$\mathrm{PCl}_5(\mathrm{~g}) \square \quad \mathrm{PCl}_3(\mathrm{~g})+\mathrm{Cl}_2$ (g) One mole of $\mathrm{PCl}_5$ is dissociated into two moles of $\mathrm{PCl}_3$ and $\mathrm{Cl}_2$ in the same phase hence, the process is endothermic i.e., $\Delta \mathrm{H}>0$. Also $\Delta \mathrm{S}>0$ as one mole of gaseous reactant gives two moles of gaseous products and randomness increases.
COMEDK-2018
Thermodynamics
272737
A piece of ice kept at room temperature melts of its own. This reaction is governed by which law?
1 Zeroth law of Thermodynamics
2 Third law of Thermodynamics
3 First law of Thermodynamics
4 Second law of Thermodynamics
Explanation:
When ice changes into water spontaneously at room temperature, the randomness increases, so entropy increases which is in accordance with the second law of thermodynamics. - The zeroth law of thermodynamics states that if two bodies are each in thermal equilibrium with some third body, then they are also in equilibrium with each other. - The third law of thermodynamics state that the entropy of a system become constant at absolute zero temperature.
GUJCET-2008
Thermodynamics
272738
Which of the following is not an intensive property?
1 Entropy
2 Melting point
3 Specific gravity
4 Refractive index
Explanation:
Intensive property - An intensive property is one that does not depend on the mass of the substance or system. Example- Temperature, pressure, density etc. Extensive property - An extensive property is a property that depends on the amount of matter or mass in a sample. Example- Enthalpy, entropy, internal energy etc.
Shift-I
Thermodynamics
272765
The second law of thermodynamics says that in a cyclic process
1 work cannot be converted into heat
2 heat cannot be converted into work
3 work cannot be completely converted into heat
4 heat cannot be completely converted into work
Explanation:
According to second law of thermodynamics- - No cyclic process that converts heat entirely into work is possible. - Work can never be equal to $Q$. - Some energy must always be transferred as heat to the system's surrounding.
