Question
Question: Calcium carbonate reacts with aqueous \(HCl\) to gives \(CaC{l_2}\) and \(C{O_2}\) according to the ...
Calcium carbonate reacts with aqueous HCl to gives CaCl2 and CO2 according to the reaction CaCO3(s)+2HCl(aq)→CaCl2(aq)+CO2(g)+H2O(l) . The mass of CaCO3 which is required to react completely with 25ml of 0.75M HCl is:
(A) 1.825g
(B) 0.9375g
(C) 1.8357g
(D) 0.46875g
Solution
First we have to know the molar mass of a chemical compound is defined as the mass of a sample of that compound divided by the amount of substance in that sample, measured in moles. The molar mass is a bulk, not molecular, property of a substance. The molar mass of a compound is calculated by adding there standard atomic masses in (molg) of each atom.
Complete step by step answer:
Since, we have to calculate the mass of calcium carbonate (CaCO3) , Let us calculate the mass of calcium carbonate (CaCO3) is x grams.
Molar mass x of CaCO3 is the sum of the masses of calcium +carbon + 3 oxygen = 40+12+48 =100g .
In the calcium carbonate(CaCO3), the molar mass is 100g
1000ml Of 0.75HCl =0.75 mole
So, 25ml of hydrochloric acid (HCl) will contain HCl$ = 0.75 \times \dfrac{{25}}{{1000}} = 0.018752molofhydrochloricacid\left( {HCl} \right)reactswith1molofCaC{O_3}So,0.01875molofhydrochloricacid\left( {HCl} \right)willreactwith\dfrac{1}{2} \times 0.01875 = 0.009375Molarmassofcalciumcarbonate\left( {CaC{O_3}} \right) = 100gHence,themassof0.009375molofcalciumcarbonateCaC{O_3} = no.ofmoles \times molarmassMassofcalciumcarbonate\left( {CaC{O_3}} \right) = 0.009375 \times 100g. = 0.9375g.∗∗Hence,thecorrectoptionis\left( C \right)$ .**
Additional information: The molar mass is the mass of a given chemical element or chemical compound (g) divided by the amount of substance (mol) .
Note:
We must know the definition of atomic mass unit is the atomic mass of an element is the average mass of the atoms of an element measured in atomic mass unit (amu, also as Daltons, D). Where 1amu=1.6605×10−24g .