Question

How many molecules are there in 122 grams of NO2?

Answer 1

NO2=14+32=46g.
No of molecules=122/46=2.65 molecules

Answer 2

$16.0\times 10^2^3$ molecules are there in 122 grams of $NO_2.$.

Given:

Mass of $No_2$ given to us is 122 g.

Explanation:

$Number of moles = \frac {mass} {Atomic weight}$

To find out the atomic weight of $NO_2$ is $14+(2\times16)=14+32=46.$.

$\frac {122}{46} = 2.652.$.

To find out the molecules we need to multiply with the atomic number $2.652\times 6.022\times10^2^3.$

= $15.97 \times 10^2^3$ which is also written asby follows

= Therefore the number of molecules is$16.0 \times 10^2^3.$.