Q1: Avogadro number is the number of molecules in one __________ of a gas.

ANS:C - gm.mole

"gm.mole" is not a standard unit in chemistry or physics. It seems like a combination of the unit for the amount of substance, which is the mole (mol), and the unit for mass, which is the gram (g). In chemistry, the term "mole" (mol) represents a specific amount of substance. One mole of any substance contains Avogadro's number (𝑁𝐴NA​) of particles, which is approximately 6.022×10236.022×1023 particles. These particles could be atoms, molecules, ions, or any other type of elementary entities. On the other hand, the gram (g) is a unit of mass, commonly used to measure the amount of substance. When we refer to "grams per mole" (g/mol), it represents the molar mass of a substance, which is the mass of one mole of that substance. Molar mass is expressed in units of grams per mole (g/mol). For example:

• The molar mass of carbon dioxide (𝐶𝑂2CO2​) is approximately 44.01 g/mol. This means that one mole of carbon dioxide molecules has a mass of 44.01 grams.
• The molar mass of water (𝐻2𝑂H2​O) is approximately 18.015 g/mol. This means that one mole of water molecules has a mass of 18.015 grams.