Question

Solid sodium reacts violently with water, producing heat, hydrogen, gas, and sodium hydroxide. How many molecules of hydrogen gas are produced when 27.5g of sodium are added to water? Show your work

Answer 1

.598 moles of H2

Find the balanced equation of the reaction

2Na + 2 H2 0 ====> 2 Na OH + H2

27.5 gm of Na is 27.5/ 22.989 =1.196 moles

from the equation, each mole of Na produces 1/2 mole of H2

1.196 moles * 1/2 = .598 moles of H2

Answer 2

Moles of sodium

• Given mass/molar mass
• 27.5/23
• 1.196mol

2 mol Na produces 1 mol H2

1 mol produces 0.5mol H2

1.196 mol produces 0.598mol

No of molecules

• 0.598×6.023×10²³
• 3.6×10²³molecules