Question

Question 1 (1 point)
How many atoms are in 223 g of cesium?

Answer 1

Answer : The correct option is (b)
`1.01* 10^(24)`

Explanation : Given,

Mass of cesium = 223 g

Molar mass of cesium = 133 g/mole

First we have to calculate the moles of cesium.

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

Now putting all the given values in this formula, we get:

`\text{Moles of cesium}=(223g)/(133g/mol)=1.67mol`

Now we have to calculate the number of atoms of cesium.

As, 1 mole of cesium contains
`6.022* 10^(23)` atoms of cesium

So, 1.67 mole of cesium contains
`1.67* 6.022* 10^(23)=1.01* 10^(24)` atoms of cesium

Therefore, the number of atoms of cesium are
`1.01* 10^(24)`