Question

What is the mass of .1 mole of magnesium atoms?

Answer 1

`2.43` `"g"`

Explanation:

We're asked to find the mass of `0.1` `"mol Mg"`.

To solve this, along with any mass-to-mole conversion, we need to know the molar mass of the substance.

On most periodic tables, for each element there is a mass number under the element's symbol. This is the mass of one mole of that element, called its molar mass. For magnesium, this is `color(red)(24.30` `color(red)("g/mol"`.

Using dimensional analysis, we can convert the given mole number (`0.1` `"mol"`) to grams:

`0.1cancel("mol Mg")((color(red)(24.30)color(white)(l)color(red)("g Mg"))/(1cancel("mol Mg"))) = color(blue)(2.43` `color(blue)("g Mg"`

Thus, `0.1` mole of magnesium atoms has a mass of `color(blue)(2.43` `sfcolor(blue)("grams"`..