1.
The perfect example of an ideal gas is
Correct Answer
D. None of the above
Explanation
None of the options provided (air, hydrogen, water vapor) can be considered as a perfect example of an ideal gas. An ideal gas is a theoretical concept that follows certain assumptions, such as having particles with negligible volume and no intermolecular forces. While air, hydrogen, and water vapor exhibit gas-like behavior, they deviate from the ideal gas behavior to some extent due to factors like intermolecular forces and non-negligible particle volume. Therefore, none of the given options can be considered a perfect example of an ideal gas.
2.
What is an ideal gas?
Correct Answer
A. Which obeys the law pv = RT
Explanation
An ideal gas is a theoretical concept in physics and chemistry that follows the ideal gas law, which states that the product of pressure (p) and volume (v) is directly proportional to the product of the number of moles of gas (n) and the temperature (T), represented by the gas constant (R). The equation pv = RT is a representation of this law, where p is the pressure, v is the volume, R is the gas constant, and T is the temperature. Therefore, the correct answer is "which obeys the law pv = RT."
3.
According to the Avogadro's law, what is the relation between volume of 1 kg mol of oxygen and volume of 1 kg mol of nitrogen, at normal pressure and temperature? (Mass of 1 kg mol of oxygen is 32 kg and mass of 1 kg mol of nitrogen is 28 kg)
Correct Answer
C. Volume of 1 kg mol of oxygen is same as that of nitrogen
Explanation
According to Avogadro's law, equal volumes of gases at the same temperature and pressure contain the same number of molecules. Since both oxygen and nitrogen have the same number of moles (1 kg mol) and are at the same temperature and pressure, their volumes will be the same. Therefore, the correct answer is that the volume of 1 kg mol of oxygen is the same as that of nitrogen.
4.
In which condition can real gas closely obey the ideal gas equation?
Correct Answer
A. Pressure is very small and temperature is very high
Explanation
Real gases closely obey the ideal gas equation when the pressure is very small and the temperature is very high. At low pressures, the intermolecular forces between gas molecules become negligible, allowing the gas to behave more like an ideal gas. Additionally, at high temperatures, the kinetic energy of the gas molecules increases, causing them to move more rapidly and collide with each other less frequently. This combination of low pressure and high temperature reduces the effects of intermolecular forces and allows the gas to closely follow the ideal gas equation.
5.
The volume occupied by one number of unit mol of gas is called as
Correct Answer
C. Molar volume
Explanation
The term "molar volume" refers to the volume occupied by one mole of a gas at a specific temperature and pressure. It is a measure of the amount of space that one mole of gas particles occupies. The molar volume is a useful concept in chemistry as it allows for easy comparison of gas volumes and is often used in stoichiometric calculations and the ideal gas law.
6.
What is the volume of a gram mole of hydrogen at 760 mm Hg and 0 °C ?
Correct Answer
B. 22.4 liters
Explanation
At standard temperature and pressure (STP), which is 0 °C and 760 mm Hg, one mole of any ideal gas occupies a volume of 22.4 liters. Therefore, the correct answer is 22.4 liters.
7.
What is a mole of a substance?
Correct Answer
B. One mole has a mass numerically equal to the molecular weight of the substance
Explanation
One mole of a substance is defined as the amount of that substance that contains the same number of particles (atoms, molecules, or ions) as there are atoms in exactly 12 grams of carbon-12. The mass of one mole of a substance is numerically equal to its molecular weight (or molar mass) in grams. Therefore, the correct answer is "One mole has a mass numerically equal to the molecular weight of the substance."