Question

PLEASE HELP ME

what would be the mass of 9.03 x 1021 molecules of hydrobromic acid (HBr)?

Answer 1

We know 1 mole of any atom or molecules contains
`6.033 * 10^(23)` atom or molecules.

1 mole of HBr i.e 81 gm/mol contains
`6.033 * 10^(23)` atom or molecules.

So, mass of
`9.03* 10^(21)` molecules is :

`m=(81* 9.03* 10^(21) )/(6.033 * 10^(23))\\\\m= 1.21\ gm`

Therefore, mass of
`9.03* 10^(21)` molecules is 1.21 gm .

Hence, this is the required solution.