Question

4) Deduce the no.of molecules of the following compound in the given quantities
a) 90 g of water
b) 7.1 g chlorine​

Answer 1

Answer:

A). Mass of 1 mole water = 16 + 1*2 = 18 u

Here No. of moles = Given mass / Mass in 1 mole water

So no. of moles = 90/18 = 5

We know that No. of molecules = No. of moles *

6.022 * 10^23

Now no. of molecules = 5 * 6.022 * 10^23

= 30.110 * 10^23

= 3.011 * 10^24 molecules

B} Similarity we do it:

Mass of 1 mole Chlorine = 35.5 u

No. of moles = 35.5/7.1

= 5

Now no. of molecules = 5 * 6.022 * 10^23

= 30.110 * 10^23

= 3.011 * 10^24 molecules