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

ya the answers 1.11g

takin' that same test with u dudes

Step-by-step explanation:

Answer 2

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}}=(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
`(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* \text{Molar mass of }H_2`

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

Therefore, the theoretical yield of hydrogen is, 1.11 grams