50 mL sodium hydroxide contains 0.050 mole of hydroxide ions mixed with a solution of hydrochloric acid containing more than 0.050 moles of hydrogen ions. How many moles of water were formed?

Answer 1

Write the correctly balanced equation for the reaction that is taking place:

NaOH + HCl ==> NaCl + H2O

1 mole NaOH reacts with 1 mole HCl to produce 1 mole H2O and 1 mole NaCl

Moles of OH^- (NaOH) present = 0.050 moles

Since there is excess HCl (more than 0.050 moles), the amount of H₂O produced is dependent ONLY on the amount (moles) of OH^- (NaOH).

From the balanced equation:

0.050 moles OH^- x 1 mole H₂O / mole OH^- ==> 0.050 moles H₂O formed.