Respuesta :
Answer:81.6%
Explanation:
Mass of CaCO3=4.010 g
Molar mass of CaCO3= 40+12+(16×3) = 100 g/mol.
Recall: number of moles(n)= mass÷ molar mass.
n=4.010÷100 = 0.0401 mol.
Molar mass of CaCl2 = 40+71= 111 g/mol.
Number of mol of CaCl2 = 5.455÷111= 0.04914 g/mol.
Mass of CaCl2 = 0.0401 × 111 = 4.4511 g of CaCl2.
Percent by mass of CaCl2 = (4.4511÷5.455) × 100
= 0.815967 ×100 = 81.5967%
Approximately; 81.6%.
Answer: The mass percent of calcium chloride in the sample is 81.6 %
Explanation:
To calculate the number of moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] .....(1)
Given mass of calcium carbonate = 4.010 g
Molar mass of calcium carbonate = 100 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of calcium carbonate}=\frac{4.010g}{100g/mol}=0.0401mol[/tex]
The chemical equation for the reaction of calcium chloride and potassium carbonate follows:
[tex]CaCl_2+K_2CO_3\rightarrow CaCO_3+2KCl[/tex]
By Stoichiometry of the reaction:
1 mole of calcium carbonate is produced from 1 mole of calcium chloride
So, 0.0401 moles of calcium carbonate will be produced from = [tex]\frac{1}{1}\times 0.0401=0.0401mol[/tex] of calcium chloride
Now, calculating the mass of calcium chloride by using equation 1:
Molar mass of calcium chloride = 111 g/mol
Moles of calcium chloride = 0.0401 moles
Putting values in equation 1, we get:
[tex]0.0401mol=\frac{\text{Mass of calcium chloride}}{111g/mol}\\\\\text{Mass of calcium chloride}=(0.0401mol\times 111g/mol)=4.451g[/tex]
To calculate the mass percentage of calcium chloride in sample, we use the equation:
[tex]\text{Mass percent of calcium chloride}=\frac{\text{Mass of calcium chloride}}{\text{Mass of sample}}\times 100[/tex]
Mass of sample = 5.455 g
Mass of calcium chloride = 4.451 g
Putting values in above equation, we get:
[tex]\text{Mass percent of calcium chloride}=\frac{4.451g}{5.455g}\times 100=81.6\%[/tex]
Hence, the mass percent of calcium chloride in the sample is 81.6 %
