Question

2H2+O2 —-> 2H2O when 18g of water are produced, how many grams of hydrogen must react

Answer 1

Mass of hydrogen = 2 g

Step-by-step explanation:

Given data:

Mass of water = 18 g

Mass of hydrogen react = ?

Solution:

First of all we will write the balance chemical equation,

2H₂ + O₂ → 2H₂O

Number of moles of water = mass / molar mass

Number of moles of water = 18 g/ 18 g/mol

Number of moles of water = 1 mol

Now we compare the moles of water and hydrogen from balance chemical equation.

H₂ : H₂O

2 : 2

1 : 1

Mass of hydrogen = number of moles / molar mass

Mass of hydrogen = 1 mol × 2 g/mol

Mass of hydrogen = 2 g