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

Question

b) How many molecules of a gas will be produced?

Please show me how to get to the solution also. Thanks!

Answer 1

The balanced reaction is :
Zn + 2 HCl ==> ZnCl2 + H2
Atomic weight Zn = 65.37 g/mol
4.30 g / 65.37 = 0.0658 mole Zn
The ratio between Zn and HCl is 1 : 2
Moles HCl = 0.0658 x 2 = 0.132
Molecular weight HCl = 36.46 g/mol
0.132 mol x 36.46 g/mol = 4.81 grams
b) the ratio between Zn and H2 is 1 : 1 so we would get 0.0658 mole of H2
Molecules H2 = 0.0658 x 6.02 x 10^23 = 3.96 x 10^22

Answer 2

Ok so you know that HCl+ Zn goes to ZnCl2( check to see if Zn has a valency of 2 or 1) and H2. First balance that equation. Now convert your grams of Zn into moles. To convert it into moles you need to know Zn's molecular weight( you can find that in the periodic table: the units for molecular weight are grams/mole)). Then from moles of Zn convert it into moles of HCl( you will know that if you balance the equation; just use the coefficents). Then find the Molecular weight of HCl( molecular weight will be in grams/mole). That's the answer to the first part.

Answer 3

First, an equation:
2 HCl + Zn = ZnCl2 + H2(gas)
This tell us that 2 moles of HCl are needed to react with 1 g-atom of Zn. Here we have
4.3/(At Wt of Zn) g-atoms, so we need 2 as many moles of HCl. Each mole weights 37 g.

By the equation, each mole of HCl produces 1/2 moles of the H2 dimer. We know the moles of HCl we used, so we can calculate the moles of the H2 dimer. Multiply this by Avagadro's # to get molecules.

Answer 4

I mean no offense at this, but this question requires a bit of thinking. More than can be recompensed by a simple "thanks."