Question

How you will convert the mass of a given a sample to the number of moles and vice versa?

Answer 1

Although there is no physical way of measuring the number of moles of a compound, we can relate its mass to the number of moles by using the compound's molar mass as a direct conversion factor. To convert between mass and number of moles, you can use the molar mass of the substance.

Answer 2

Answer:

• A substance molar mass is calculated by multiplying its relative atomic mass by the molar mass constant(1 mg/mole).

• The molar mass constant can be used to convert mass to moles.
• By multiplying a given mass by the molar mass or molecular weight, the amount of moles of the substances can be calculated.

Explanation:

The above Answer can be explained with an example followed here:

Q: What is the mass of 2.5mole H2O?

Given: 2.5 mole of H2O

Molar mass=

H- molecular weight*2=

1.01*2=

2.02

O-molecular weight*1=

16.00*1=

16.00

Adding the both

2.02+16.00=

18.02 g/mol.

For Solution:-

2.5mol H2O(18.02g H2O/1mol of H2O)=

on cancellation of H2O from denominator to up and cross calculating the ans is

45.05g H2O.

This is the mass of 2.5 mole H2O.