Question

A chemist determines by measurements that 0.030 moles of hydrogen gas participate in a chemical reaction. Calculate the mass of hydrogen gas that participates. Be sure your answer has the correct number of significant digits.

Answer 1

0.060 g

Step-by-step explanation:

Hydrogen gas is made up of 2 atoms of hydrogen
`H_2(g)`.

From the formula for calculating mole:

mole = mass/molar mass

Molar mass of hydrogen gas = 2.016 g/mol

Hence, 0.030 mole hydrogen gas would weigh:

mass = molar mass x mole

= 2.016 x 0.030

= 0.06048 g

The mass of hydrogen gas that participated to the correct number of significant digits is, therefore, 0.060 g