Answer: 4.87 g
Explanation:
We know that for every 3 moles of zinc that are consumed, 3 moles of hydrogen are produced (we can reduce this to the number of moles of zinc consumed = moles of hydrogen produced)
We know that the formula mass of hydrogen is 2(1.00794)=2.01588 g/mol, so in 0.15 g, there is about 0.15/2.01588 = 0.074409191023275 moles.
This means that about 0.074409191023275 moles of zinc are needed, and since the atomic mass of zinc is 65.409 g/mol, the answer is (0.074409191023275)(65.409)=4.87 g
