The purity of a 0.248 gram sample containing Zn is determined by measuring the amount of hydrogen gas formed when the sample reacts with hydrochloric acid. The sample is found to be 91.7% Zn. What volume of hydrogen gas in liters was collected at STP?
There are multiple steps in this problem:
1) First you have to set up the chemical reaction
2Zn + 2HCl = H2 +2ZnCl
2) Now you have to convert 0.248 g into moles
1 mole of Zn = 65.409 ...
This solution takes you through four steps: set up the chemical reaction, convert 0.248 g into moles, from the number of moles of Zn find the number of moles of H2, with the number of moles of H2 find the volume of gas using the formula: V = (nRT)/P. 150 words.