Question

How many molecules of nitrogen dioxide are in 1.28 g of nitrogen dioxide NO2?

Answer 1

Hello!

How many molecules of nitrogen dioxide are in 1.28 g of nitrogen dioxide NO2?

Let's first find the molecular mass of nitrogen dioxide, knowing that by Avogadro's Law for each mole of a substance we have 6.02 * 10²³ molecules.

N = 1*14 = 14 amu

O = 2*16 = 32 amu

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molecular mass of nitrogen dioxide = 14 + 32 = 46 g/mol

How many molecules of nitrogen dioxide are in 1.28 g of nitrogen dioxide NO2?

46 g ---------------- 6.02*10²³ molecules

1.28 g ------------- y molecules

`46*y = 1.28*6.02*10^(23)`

`46y = 7.7056*10^(23)`

`y = (7.7056)/(46)*10^(23)`

`y = 0.167513043*10^(23)`

`\boxed{\boxed{y \approx 1.675*10^(22)\:molecules\:of\:nitrogen\:dioxide}}\end{array}}\qquad\checkmark`

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I Hope this helps, greetings ... Dexteright02! =)

Answer 2

Answer: 1.675 X
`10^(22)` molecules

Reason:
1 mole of any substance contains Avagadro's number (i.e. 6.022 X
`10^(23)` ) of molecules.

For NO2, molecule weight = 46 g/mol.
Thus, 1 mol (46 g/mol) of NO2 contains 6.022 x
`10^(23)` molecules.
Therefore, 1.28 g of NO2 contains 1.675 X
`10^(22)` molecules.