Question

Answer the two questions for 15pts

Answer 1

For 1: 6.68 g of nitrogen dioxide will contain
`8.73* 10^(22)` number of molecules

For 2: The given amount of nitrogen dioxide molecules has a mass of 41.31 g.

Step-by-step explanation:

According to the mole concept:

1 mole of a compound contains
`6.022* 10^(23)` number of molecules

The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:

`\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}` ......(1)

• For 1:

We are given:

Mass of nitrogen dioxide = 6.68 g

Molar mass of nitrogen dioxide = 46 g/mol

Putting values in equation 1, we get:

`\text{Moles of nitrogen dioxide}=(6.68g)/(46g/mol)=0.145mol`

Using above concept:

If 1 mole of a compound contains
`6.022* 10^(23)` number of molecules

So, 0.145 moles of nitrogen dioxide will contain =
`(0.145* 6.022* 10^(23))=8.73* 10^(22)` number of molecules

Hence, 6.68 g of nitrogen dioxide will contain
`8.73* 10^(22)` number of molecules

• For 2:

We are given:

Molecules of nitrogen dioxide =
`5.41* 10^(22)` molecules

Using the above concept:

If
`6.022* 10^(23)` number of molecules are present in 1 mole of a compound

So,
`5.41* 10^(22)` number of molecules will be present in =
`(1mol)/(6.022* 10^(23))* 5.41* 10^(22)=0.898` moles of nitrogen dioxide

We know, molar mass of nitrogen dioxide = 46 g/mol

Using equation 1:

`0.898mol=\frac{\text{Mass of nitrogen dioxide}}{46g/mol}\\\\\text{Mass of nitrogen dioxide}=0.898mol* 46g/mol=41.31g`

Hence, the given amount of nitrogen dioxide molecules has a mass of 41.31 g.