can someone check my answers thank you.

Question

1)How many grams of hydrochloric acid are required to react completely with 4.30 grams of zinc?

answer: 0.1328 g H2

2)How many molecules of gas will be produced?

answer: 0.395x10^23 molecules

Answer 1

1)You misread the first question.
You DO have the correct amount of H2 formed.

They are asking for the amount of HCl needed, not the amount of H2 produced. The atomic mass of Zn is 65.4 g/mol and the reaction is
2 HCl + Zn -> ZnCl2 + H2
You start with 0.06575 moles of Zn. You require twice as many moles of HCl, which is 0.1315 moles. Convert that to grams.

2) You form 0.06575 moles of H2. The other product is not a gas. You multiplied that number of moles by Avogadro's number and got the right answer.

Answer 2

So the answer to number one would be 4.7 grams of HCl and once again I got the answer to number 2 right? just checking

Answer 3

One more question...reading through what you just wrote I see 0.06575 moles for both Zn and H2?...I thought it was just be for one of them...sorry maybe Im just confusing myself.

Answer 4

I would have rounded the answer to 4.8 and the answer to #2 I would have rounded to the digits 396.

Answer 5

Perhaps you aren't understanding what the equation tells you.
Zn + 2HCl ==> ZnCl2 + H2.
The equation tells us that 1 mol of Zn reacts with 2 mols HCl to produce 1 mol ZnCl2 AND 1 mol H2.
So if we start with 4.3 g Zn, we have 4.3/65.4 = 0.06575 mol Zn metal. That IMMEDIATELY tells us that we also have 0.06575 mol ZnCl2 and 0.06575 mol H2 as well as 2 x 0.06575 = 0.1315 mol ZnCl2 (assuming, of course, that we use all of the zinc).