Question

Aqueous sulfuric acid h2so4 will react with solid sodium hydroxide naoh to produce aqueous sodium sulfate na2so4 and liquid water h2o . suppose 89.3 g of sulfuric acid is mixed with 96. g of sodium hydroxide. calculate the minimum mass of sulfuric acid that could be left over by the chemical reaction. be sure your answer has the correct number of significant digits.

Answer 1

1) Balanced chemical equation

H2SO4 + 2NaOH ---> Na2 SO4 + 2H2O

=> 1 mol H2SO4 : 2 moles NaOH

2) Convert 89.3 g of H2SO4 and 96.0 g of NaOH to moles

Molar mass of H2SO4 = 98.1 g/mol

Molar mass of NaOH = 40.0 g/mol

moles = mass in grams / molar mass

moles H2SO4 = 89.3 g / 98.1 g/mol = 0.910 mol

moles NaOH = 96.0 g / 40.0 g/mol = 2.40 mol

3) Theoretical molar ratio = 2 moles NaOH / 1 mol H2SO4

So, all the 0.91 mol of H2SO4 will be consumed along with 1.820 (2*0.91) moles of NaOH, and 0.580 moles (2.40 - 1.82) of NaOH will be left over by the chemical reaction.

4) Convert 0.580 moles NaOH to mass

0.580 moles * 40.0 g/mol = 23.2 g of NaOH will be left over