# A chemist weighed out 3.89 g of nickel. What is the number of moles of nickel she weighed out?

Apr 17, 2016

She measured out 0.0663 mol of nickel.

#### Explanation:

For this question, we need to use the Periodic Table to find the molar mass of $\text{Ni}$ (58.69 g/mol).

The formula for molar mass is

color(blue)(|bar(ul(color(white)(a/a) "molar mass" = "mass"/"moles"color(white)(a/a)|)))" "

We can rearrange the formula to read

$\text{moles" = "mass"/"molar mass}$

$\text{moles" = 3.89 color(red)(cancel(color(black)("g Ni"))) × "1 mol Ni"/(58.69 color(red)(cancel(color(black)("g Ni")))) = "0.0663 mol Ni}$