Hydrogen gas is produced when zinc reacts with hydrochloric acid. If the actual yield of this reaction is 85%?
how many grams of zinc are needed to produce 112 l of H2 at STP?

a. 95 g
b. 180
c. 280
d.380

Okay, I got the formula for this. I got that if it was 100% yield I would need 277.95 grams. So what do I do with the 85% yield?
The answer is D btw. I just multiplied 277x0.85.. but that doesn't work...

Question

Hydrogen gas is produced when zinc reacts with hydrochloric acid. If the actual yield of this reaction is 85%?
how many grams of zinc are needed to produce 112 l of H2 at STP?

a. 95 g
b. 180
c. 280
d.380

Okay, I got the formula for this. I got that if it was 100% yield I would need 277.95 grams. So what do I do with the 85% yield? 
The answer is D btw. I just multiplied 277x0.85.. but that doesn't work...

anonymous · Answer

Wait, I got it. It's cuz actual yield/theoretical yield=percent yield therefore. 
277/0.85. 
KK