NE121 Lecture : Tutorial Question 5 Gives the problem and solution to tutorial question 5

• School: University of Waterloo
• Department: Nanotechnology Engineering
• Course: NE121
• Professor: Laura Deakin

Document Summary

A student gave you 1. 20g of naoh (s) and told you it contained ca(oh)2. To this you add lead nitrate solution (pb(no3)2) which produces 3. 67 g of lead hydroxide (pb(oh)2)) precipitate. What was the percentage by mas of naoh in the original mixture. 2naoh (s) + (pb(no3)2) (aq) 2nano3 (s) + pb(oh)2 (aq) Ca(oh)2 (aq) + pb(no3)2 (aq) ca(no3)2 (aq) + pb(oh)2 (s) = all moles of ca(oh)2 reacted + half moles of naoh reacted. 0. 01521 moles = (moles of naoh) + moles ca(oh)2. Let x be the mass of naoh reacted: this is what you are looking for to get % mass.