2HCL(aq) + Zn(s) -> ZnCl^2(aq) + H^2(g)

Question

the molar mass of hydrogen is 1 g/mol, the molar mass of chlorine is 35 g/mol, and the molar mass of zinc is 65 g/mol. when 130 grams of zinc react completely in hydrochloric acid, how much is the total mass of the products?
A 144 g
B. 130 g
C. 270 g
D. 274 g

Answer 1

To determine the total mass of the products, we first need to balance the chemical equation:

2HCl(aq) + Zn(s) -> ZnCl2(aq) + H2(g)

Looking at the equation, we see that for every 2 moles of HCl that react, 1 mole of Zn is consumed.

Step 1: Find the number of moles of Zn in 130 grams.
Molar mass of Zn = 65 g/mol
Number of moles = Mass / Molar mass = 130 g / 65 g/mol = 2 moles

Step 2: Since 1 mole of Zn is consumed when balancing the equation, we know that 1 mole of ZnCl2 and 1 mole of H2 are produced.
Therefore, the molar mass of ZnCl2 = 65 g/mol + 2(35 g/mol) = 135 g/mol
The molar mass of H2 = 2(1 g/mol) = 2 g/mol

Step 3: Calculate the total mass of the products.
Total mass = (number of moles of ZnCl2 x molar mass of ZnCl2) + (number of moles of H2 x molar mass of H2)
Total mass = (2 moles x 135 g/mol) + (2 moles x 2 g/mol) = 270 g + 4 g = 274 g

Therefore, the total mass of the products when 130 grams of zinc react completely in hydrochloric acid is 274 grams.

The correct answer is D. 274 g.