MCQ
Q.
Among the following, the one with the highest mass is:
Correct Answer: B
Concept:
- The laws dealing with ideal gases naturally called ideal gas laws, and the laws determined in the seventeenth century by Boyle's observational work and in the eighteenth century by Charles.
- The Boyles Law states that the gas pressure is inversely proportional to the gas volume for a given mass of gas stored at a constant temperature.
- Charles Law states that the gas volume is directly proportional to the gas temperature for a given fixed mass of gas stored at a constant pressure.
- An ideal gas is a gas that follows the equation:
PV = nRT at all temperatures and pressure, where P = Pressure of the ideal gas. V = Volume of the ideal gas n = Amount of ideal gas measured in terms of moles
R = Universal gas constant T = Temperature
Mole Concept -
- The quantity one mole of a substance signifies 6.022 × 1023 number of particles of that substance which may be atoms, molecules, or ions.
- The quantity is a universal constant like Dozen, Gross, etc., and is known as Avogadro number, denoted by NA. after the scientist Amedeo Avogadro.
- Examples- In one mole of H2, there are 6.022 × 1023 molecules of hydrogen, and the number of atoms is 2 × 6.022 × 1023, as one molecule of hydrogen contains two-atom each.
- The mass of one mole of a substance is called its Molar Mass (M) or Atomic mass expressed in grams.
- The volume occupied by a mole of gas is 22.4 L at NTP, called its Molar Volume.
- The no. of moles (n) is calculated as =
The number of particles / Avogadro’s number.
To summarise, we can say,
Calculation:
- The molar mass of 1 mole of H2SO4 is =
2 × 1 + 32 + 4 × 16 = 98g
- The molar mass of 1 mole of Silver, Ag is its molecular mass 108g.
- The molar mass of CO2 is = 12 + 2× 16 = 44g.
- 44g of CO2 means one mole.
- 1 mole of Oxygen weighs 16 + 16 = 32g.
- Hence, the highest mass is of 1 mole of Ag.
