Limestone dissolves in hydrochloric acid for form calcium chloride, carbon dioxide, and water. How many moles of HCl are required to dissolve 205g of limestone? How many moles of water are formed?
Answers
Explanation:
Expert's answer
Write the reaction:
CaCO3+2HCl→CaCl2+CO2+H2O.
We have 205 g of chemically pure limestone. How many moles is this?
n_l=\frac{m}{\Mu}=\frac{205}{40+12+16\cdot3}=2.05\text{ mol}.n
l
=
M
m
=
40+12+16⋅3
205
=2.05 mol.
What is a mole? It's the amount of substance that contains a specific number of particles. Therefore, 2.05 moles of any substance contains equal number of particles. This is the key to proceed: we need exactly 2.05 moles of HCl to react with limestone. But look at the reaction: it says that one molecule of CaCO3 requires two molecules of HCl, therefore, we need two times more particles for HCl, or 4.1 moles. This is equivalent to the mass of acid
Answer:
Write the reaction:
CaCO3+2HCl→CaCl2+CO2+H2O.
We have 205 g of chemically pure limestone. How many moles is this?
n_l=\frac{m}{\Mu}=\frac{205}{40+12+16\cdot3}=2.05\text{ mol}.n
l
=
M
m
=
40+12+16⋅3
205
=2.05 mol.
What is a mole? It's the amount of substance that contains a specific number of particles. Therefore, 2.05 moles of any substance contains equal number of particles. This is the key to proceed: we need exactly 2.05 moles of HCl to react with limestone. But look at the reaction: it says that one molecule of CaCO3 requires two molecules of HCl, therefore, we need two times more particles for HCl, or 4.1 moles. This is equivalent to the mass of acid
m=n\Mu=4.1\cdot(1+35.5)=149.7\text{ g}.m=nM=4.1⋅(1+35.5)=149.7 g.
According to the reaction, one molecule of limestone produces one molecule of water, thus, for water
n=2.05\text{ mol},\\ m=n\Mu=2.05(1\cdot2+16)=36.9\text{ g}.n=2.05 mol,
m=nM=2.05(1⋅2+16)=36.9 g.