Question

Calculate the no. Of Na2CO3 molecule and no. Of oxygen atoms in 21.2g of Na2CO3

Please!!!!!

Answer 1

For this we first need to find number of mole of Na2Co3,then mole of oxygen

Now mole=given weight /molecular weight

Here molecular weight of Na2Co3 =2 ✖ 23+12+16 ✖ 3=106

So mole of Na2Co3 =21.2/106=0.2

Now, 1mole of Na2Co3 contains 3

Mole of oxygen so

Mole of oxygen =3 times 0.2 =0.6

Now for numbers of oxygen atom we just multiply this mole with avogadro number.

Avogadro number :-6.022 ✖ 10^23

So finally total atoms Of oxygen =

6.022 ✖ 10^23 ✖ 0.6=
3.61 ✖ 10 ^23