If 18.7 ml of 0.800 m hcl solution are needed to neutralize 5.00 ml of a household ammonia solution, what is the molar concentration of the ammonia? nh3 (aq) + hcl (aq) →nh4cl (aq)

2.99 m Looking at the balanced equation, it takes 1 mole of HCl to neutralize 1 mole of NH3. So you can multiply the volume of both reactants by their molarity and set them equal to each other. The expression is 18.7 * 0.800 = 5.00 * x And solve for x. 14.96 = 5.00 x 2.992 = x So the molar concentration of the ammonia used is 2.992 m. Since we have 3 significant figures, the result rounded to 3 significant figures is 2.99 m