1. Which law states that the volume of a given mass of a gas is directly proportional to its temperature at constant pressure?
Answer:
Explanation:
Charles's Law states V ∝ T at constant pressure.
2. At absolute zero, the volume of an ideal gas will be:
Answer:
Explanation:
According to Charles's Law, the volume of a gas becomes zero at absolute zero.
3. Which of the following gases will have the highest rate of diffusion?
Answer:
Explanation:
According to Graham's law, lighter gases diffuse faster, and H2 is the lightest among the given options.
4. The SI unit of pressure is:
Answer:
Explanation:
The SI unit of pressure is Pascal (Pa).
5. The amount of substance which contains the Avogadro number of entities is called:
Answer:
Explanation:
A mole contains 6.022 x 10^23 entities, which is Avogadro's number.
6. If the temperature is constant, which law relates pressure and volume for a given mass of gas?
Answer:
Explanation:
Boyle's Law states P ∝ 1/V at constant temperature.
7. Surface tension is:
Answer:
Explanation:
Surface tension generally decreases with an increase in temperature.
8. The vapor pressure of a liquid ________ with an increase in temperature.
Answer:
Explanation:
With an increase in temperature, more molecules get the energy to escape into the vapor phase, thus increasing the vapor pressure.
9. Which of the following represents a condition of dynamic equilibrium in the context of liquids?
Answer:
Explanation:
At dynamic equilibrium, the rate of evaporation is equal to the rate of condensation.
10. The critical temperature is the temperature:
Answer:
Explanation:
Above the critical temperature, no amount of pressure can liquefy a gas.
11. Real gases deviate from ideal behavior at:
Answer:
Explanation:
At low temperatures and high pressures, intermolecular forces and molecular sizes become significant, causing deviations.
12. The unit of van der Waals constant 'a' is:
Answer:
Explanation:
'a' represents intermolecular attractions, and its unit is L^2 atm/mol^2.
13. Which of the following is an example of a dipole-dipole interaction?
Answer:
Explanation:
HCl molecules have a permanent dipole, leading to dipole-dipole interactions.
14. Which of the following gases is least likely to obey the ideal gas laws?
Answer:
Explanation:
NH3 has strong hydrogen bonding and deviates significantly from ideal behavior.
15. In a liquid, the intermolecular forces are:
Answer:
Explanation:
Liquids have moderate intermolecular forces, stronger than gases but weaker than solids.
16. A gas that follows the ideal gas laws under all conditions is termed as:
Answer:
Explanation:
An ideal gas strictly follows the ideal gas laws under all conditions, though it's a hypothetical concept.
17. Which of the following will have the highest boiling point?
Answer:
Explanation:
Boiling point increases with an increase in molecular size and intermolecular forces.
18. The process of a liquid changing into its vapor state at any temperature below its boiling point is called:
Answer:
Explanation:
Evaporation is a surface phenomenon that occurs below the boiling point.
19. The van der Waals equation accounts for the deviations from ideal behavior by introducing the terms:
Answer:
Explanation:
'a' accounts for intermolecular attractions, and 'b' accounts for the finite size of molecules.
20. The height to which a liquid rises or falls in a capillary tube is inversely proportional to:
Answer:
Explanation:
According to Jurin's law, the height (h) of a liquid column in a capillary tube is inversely proportional to its radius.