Question

What mass of iron(III) chloride contains 4.13 1023 chloride ions?

Answer 1

37.3g

Step-by-step explanation:

Formula of the compound:

FeCl₃

Number of chloride ions = 4.13 x 10²³ ions

First find the number of moles in this ions;

6.02 x 10²³ ions are contained in 1 mole of a substance

4.13 x 10²³ ions contains
`(4.13 x 10^(23) )/(6.02 x 10^(23) )` = 0.69mole chloride ions

Now;

3 mole of chloride ions are contained in 1 mole of FeCl₃

0.69 mole of chloride ions will contain
`(0.69)/(3)` = 0.23mole of FeCl₃

To find the mass;

Mass of FeCl₃ = number of moles x molar mass

molar mass of FeCl₃ = 55.8 + 3(35.5) = 162.3g/mol

Mass of FeCl₃ = 0.23 x 162.3 = 37.3g