What happens to a gas when it expands at constant temperature and pressure?

1. Internal energy decreases

2. Entropy increases and then decreases

3. Internal energy increases

4. Internal energy remains constant

If a gas absorbs 200 J of heat and expands by 500 ${\mathrm{cm}}^3$ against the constant pressure of 2x${10}^5$ Nm^-2, then the change in internal energy is :

1. $-$200 J

2. $-$100J

3. +100J

4. + 300J

The internal energy of a substance does not depend upon

(1) Translational energy

(2) Vibrational energy

(3) Energy due to the gravitational pull

(4) Rotational energy

Internal energy (E) and pressure of a gas of unit volume are related

as

(1) $P=\frac{2}{3}E<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>$
$$

(2) $P=\frac{3}{2}E<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>$

(3) $<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>P=\frac{E}{2}<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>$

(4) P=2E

Identify the false statement among the following.

Considering entropy (S) as a thermodynamic parameter, the criterion for the spontaneity of any process is:


1. $∆S_{system}+∆S_{surroundings}>0$

2. $∆S_{system}-∆S_{surroundings}>0$

3. $∆S_{system}>\mathrm{0\; only}$

4. $∆S_{s\mathrm{urroundings}}>\mathrm{0\; only}$

For which of the following processes will the entropy increase?

Which of the following is the correct first law thermodynamics equation?

(1) $U=∆Q-W$
$$

(2) $∆W=∆U+∆Q$
$$

(3) $∆U=∆W+∆Q$

(4) None of the above 

Which of the following conditions result in a spontaneous reaction?

1. Exothermic and increasing disorder

2. Exothermic and decreasing disorder

3. Endothermic and increasing disorder

4. Endothermic and decreasing disorder

Assume each reaction is carried out in an open container. For which of the following reactions will $∆\mathrm{H\; be\; equal\; to<mspace\; width="1em"></mspace>}∆\mathrm{U}?$

1. ${\mathrm{PCl}}_3\left(\mathrm{g}\right)$ $\to {\mathrm{PCl}}_3\left(\mathrm{g}\right)$ $+{\mathrm{Cl}}_2\left(\mathrm{g}\right)$ $$

2. $2\mathrm{CO}\left(\mathrm{g}\right)$ $+{\mathrm{O}}_2\left(\mathrm{g}\right)$ $\to 2{\mathrm{CO}}_2\left(\mathrm{g}\right)$ $$

3. ${\mathrm{H}}_2\left(\mathrm{g}\right)$ $+{\mathrm{Br}}_2\left(\mathrm{g}\right)$ $\to 2\mathrm{HBr}\left(\mathrm{g}\right)$

4. $\mathrm{C}\left(\mathrm{s}\right)$ $+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)$ $\to 2{\mathrm{H}}_2\left(\mathrm{g}\right)$ $+{\mathrm{CO}}_2\left(\mathrm{g}\right)\hspace{0.17em}$