Question

Question #c894f

Answer 1

Here's what you need to do.

Explanation:

To get the formula mass of sodium chloride, `"NaCl"`, you need to add the molar masses of its constituent atoms, sodium and chlorine.

The atomic masses of sodium and of chlorine are

`"Na: " "22.990 u"`

`"Cl: " "35.453 u"`

Since a formula unit of sodium chloride cotnains *one* sodium atom and one** chlorine atom, the formula mass of sodium chloride will be

`1 xx "22.990 u" + 1 xx "35.453 u" = "58.443 u"`

To get the percent composition of the compound, use the atomic masses of each constituent atom and the formula mass

`"For Na: " (22.990color(red)(cancel(color(black)("u"))))/(58.443color(red)(cancel(color(black)("u")))) xx 100 = "39.34% Na"`

`"For Cl: "(35.453color(red)(cancel(color(black)("u"))))/(58.443color(red)(cancel(color(black)("u")))) xx 100 = "60.66% Cl"`

So, according to the percent composition of sodium chloride, every `"100 g"` of sodium chloride will contain `"39.34%` sodium and `60.66%` chlorine.