In the reaction HCl (aq) + NaOH (aq) → NaCl (aq) + H2O (l), if 45.0 milliliters of a 2.0 M HCl react in an excess of NaOH, how many grams of H2O will be produced?

1) Chemical equation

HCl (aq) + NaOH (aq) - - > NaCl (aq) + H2O (l)

2) Molar ratios

1 mol HCl : 1 mol NaOh : 1 mol NaCl : 1 mol H2O

3) Number of moles of HCl:

M = n / V = > n = M * V = 2.0M * 0.045 l = 0.09 mol

4) Use the adequate proportion:

1mol HCl / 1 mol H2O = 0.09 mol HCl / x = > x = 0.09 mol H2O

5) Use the molar mass of H2O to convert moles to grams

=> 0.09 mol * 18.0 g/mol = 1.62 g

Answer: 1.62 g