Question

periodic table
calcium fluoride (caf₂) is a major component in human teeth. calculate the percent composition of calcium fluoride.
○ a. 48.7% ca, 51.3% f
○ b. 40.1% ca, 59.9% f
○ c. 33.3% ca, 66.7% f
○ d. 51.3% ca, 48.7% f

Explanation:

Step1: Calculate molar mass of \(CaF_2\)

Molar mass of \(Ca = 40.08\space g/mol\), molar mass of \(F= 19.00\space g/mol\).
Molar mass of \(CaF_2=40.08 + 2\times19.00=40.08 + 38.00 = 78.08\space g/mol\)

Step2: Calculate percent composition of \(Ca\)

Percent composition of \(Ca=\frac{40.08}{78.08}\times100\%\approx51.3\%\)

Step3: Calculate percent composition of \(F\)

Percent composition of \(F=\frac{38.00}{78.08}\times100\%\approx48.7\%\)

Answer:

D. \(51.3\%\space Ca, 48.7\%\space F\)