Question

A Helium Balloon contains 24.3 moles of Helium Gas. How many grams of Helium is this?

Answer 1

Answer:

C) 97.2g

Explanation:

Information given;

- Calculate Number of moles

- Mass of Helium

Before proceeding, it is important to know the relationship between number of moles, mass and molar mass.

Generally 1 mole of a atom weighs as much as its molar mass. Given that the molar mass of Helium is 4.00g/mol.

It means one mole of Helium weighs 4 g.

How grams then do 24.3 moles weigh?

1 mol = 4.00g

24.3 mol = x g

Cross multiplication yields;

x = (24.3 * 4) / 1

x = 97.2 g

Answer 2

Mass= number of moles multiply Mass of one mole
= 24.3 multiplied by 4
= 96.2