Answer:
0.27 mole
Explanation:
Data given:
mass of hydrochloric acid (HCl) = 20 g
moles of hydrogen (H₂O) = ?
Solution:
First we look to the reaction in which hydrogen react with Chlorine and make hydrochloric acid (HCl)
Reaction:
H₂ + Cl₂ -----------> 2HCl
Now look at the reaction for mole ratio
H₂ + Cl₂ -----------> 2HCl
1 mole 2 mole
So it is 1:2 mole ratio of hydrogen to hydrochloric acid (HCl)
As we Know
molar mass of H₂ = 2(1) = 2 g/mol
molar mass of HCl = 1 + 35.5 = 36.5 g/mol
Now convert moles to gram
H₂ + Cl₂ -----------> 2HCl
1 mole (2 g/mol) 2 mole (36.5 g/mol)
2 g 73 g
So,
we come to know that 2 g of hydrogen gives 73 g of hydrochloric acid (HCl) then how many grams of hydrogen will be required to produce 20 grams of hydrochloric acid (HCl).
Apply unity formula
2 g of H₂ ≅ 73 g of HCl
X g of H₂ ≅ 20 g of HCl
Do cross multiplication
X of H₂ = 2 g x 20 g / 73 g
X of H₂ = 0.55 g
Now convert grams of H₂ into moles
No. of moles = mass in grams/molar mass
Put values in above formula
No. of moles = 0.55 g / 2 (g/mol)
No. of moles = 0.27 mol
0.27 mole of hydrogen needed to produce 20 gram of hydrochloric acid (HCl).
