Question

How many molecules make up 12.8g of N2O4​

Answer 1

8.35 × 10 ²² molecules

Step-by-step explanation:

gram molecular weight of N2O4

= 2 × 14 + 4 × 16

= 28 + 64

= 92g

1 mole N2O4 has 6 × 10²³ molecules of N2O4 and weighs 92g

therfore,

92 g has = 6 × 10²³ molecules

12.8 g has =

`\frac{6 * 10 {}^(23)}{92} * 12.8`

= 0.835 × 10²³

= 8.35 × 10 ²² molecules