Question

How many milliliters of calcium, with a density of 1.55 g/mL, are needed to produce 85.8 grams of calcium fluoride in the single replacement reaction below? Show all steps of your calculation as well as the final answer.

Unbalanced equation: Ca + HF yields CaF2 + H2

Answer 1

Answer: 55.35ml

Explanation:

`Ca+2HF\rightarrow CaF_2+H_2`

To calculate the given moles, we use the formula:

`Moles=\frac{\text{Given mass}}{\text{Molar mass}}`

`Moles=(85.8g)/(78g/mol)=1.1moles`

By stoichiometry of the reaction,

1 mole of
`CaF_2` is produced by 1 mole of Ca

1.1 moles of
`CaF_2` are produced by=
`(1)/(1)* 1.1=1.1 moles` of Ca.

Mass of
`CaF_2=\text{no of moles}* \text{Molar mass}`

Mass of
`CaF_2=1.1* {78}=85.8g`

`Volume=(Mass)/(Density)`

`Volume=(85.8g)/(1.55g/ml)=55.35ml`