Question

If 40.0 g of HCl react with an excess of magnesium metal, what is the theoretical yield of hydrogen?
a. 1.11 g
b. 2.22 g
c. 52.2 g
d. 104 g

Answer 1

Answer : The theoretical yield of hydrogen is, 1.11 grams

Solution : Given,

Mass of HCl = 40 g

Molar mass of HCl = 36.46 g/mole

Molar mass of $H_2$ = 2.02 g/mole

First we have to calculate the moles of HCl.

$\text{Moles of HCl}=\frac{\text{Mass of HCl}}{\text{Molar mass of HCl}}=\frac{40g}{36.46g/mole}=1.097moles$

Now we have to calculate the moles of hydrogen.

The balanced chemical reaction will be,

$2HCl+Mg\rightarrow MgCl_2+H_2$

From the balanced reaction we conclude that,

2 moles of HCl react to give 1 mole of hydrogen

1.097 moles of HCl react to give $\frac{1.097}{2}=0.5485$ mole of hydrogen

Now we have to calculate the mass of hydrogen.

$\text{Mass of }H_2=\text{Moles of }H_2\times \text{Molar mass of }H_2$

$\text{Mass of }H_2=(0.5485moles)\times (2.02g/mole)=1.1079g=1.11g$

Therefore, the theoretical yield of hydrogen is, 1.11 grams

Answer 2

Answer:

ya the answers 1.11g

takin' that same test with u dudes

Explanation: