Question

Solid sodium metal reacts violently with water, producing heat, hydrogen gas, and sodium hydroxide. How many molecules of hydrogen are formed when 35 g of sodium are added to water? Please show work.

Answer 1

4.6 × 10²³ molecules:

Step-by-step solution

You will need a balanced equation with masses, moles, and molar masses, so let's gather the information in one place:

M_r: 22.99

2Na + 2H₂O ⟶ 2NaOH + H₂

m/g: 35

1. Calculate the moles of Na

Moles of Na = 35 g Na × (1 mol Na/22.99 g Na)

Moles of Na = 1.52 mol Na

2. Calculate the moles of H₂

Moles of H₂ = 1.52 mol Na × (1 mol H₂/2 mol Na)

Moles of H₂= 0.761 mol H₂

3. Calculate the molecules of H₂

6.022 × 10²³ molecules H₂ = 1 mol H₂

Molecules of H₂ = 0.761 × (6.022 × 10²³ /1)

Molecules of H₂ = 4.6 × 10²³ molecules H₂

The reaction forms 4.6 × 10²³ molecules of H₂.