Question

Оксид кальция массой 2.8 г. растворили в 200 г. хлороводородной кислоты. Рассчитайте массовую долю хлорида кальция в полученном растворе.

Answer 1

CaO+2HCl=CaCl2 +H2O
n(CaO)=2,8/56=0,05(моль)
n(HCl)=200/36,5=5,5(моль)
n(CaO)-недостаток
n=0,05моль  x
CaO+2HCl=CaCl2 +H2O
n=1моль        n=1моль
n(CaCl2)=0,05(моль)
m(CaCl2)=0,05*111=5,55(г)
m(раствора)=200+2,8=202,8(г)
w%(CaCl2)=5,55/202,8*100=2,737(%)
Ответ:w%(CaCl2)=2,737%

Answer 2

Calculation of the Mass Fraction of Calcium Chloride in the Solution

To calculate the mass fraction of calcium chloride in the solution, we need to determine the amount of calcium chloride and the total mass of the solution.

Given: - Mass of calcium oxide (CaO) = 2.8 g - Mass of hydrochloric acid (HCl) = 200 g

To find the mass fraction of calcium chloride, we first need to convert the mass of calcium oxide to the mass of calcium chloride. Calcium oxide (CaO) reacts with hydrochloric acid (HCl) to form calcium chloride (CaCl2) and water (H2O) according to the following balanced chemical equation:

CaO + 2HCl -> CaCl2 + H2O

From the balanced equation, we can see that 1 mole of CaO reacts with 2 moles of HCl to produce 1 mole of CaCl2. The molar mass of CaO is 56.08 g/mol, and the molar mass of CaCl2 is 110.98 g/mol.

To calculate the amount of CaCl2 formed, we can use the following equation:

Amount of Ca