Question

The no. of molecules of H2 is 333g of Al2(SO4)3.18H2O is

Answer 1

Explanation:

molar mass of the compound=666g/mol

mass of compound=333g

moles of compound=mass/molar mass=333/666

=0.5mol

in 1 molecule of compound there is 18 molecule of H2

so in 0.5 mol of compound there is 0.5×18=9mol

=9×6.02×10²³=54.18×10²³ molecules of H2

or 5.418×10²⁴

Answer 2

Given:

mass of hydrated Aluminium Sulphate, m=333g

To find:

The no. of molecules of H2 is 333g of Al2(SO4)3.18H2O

✪✪Solution✪✪

As, M.M (Molar Mass) of Al₂(SO₄)₃.18H₂O :

M.M.=2(27)+3(32+4(16))+18(2(1)+16)

M.M.=666g

As, No. of mol = given mass ÷ Molar Mass

,i.e., n=m/M.M

Thus, here

⇒n=(333/666) mol

⇒n=0.5 mol

Now, as 1 molecule of Al₂(SO₄)₃.18H₂O contains 18 molecules of H₂ (or 36 H atoms)

⇒1 mol of Al₂(SO₄)₃.18H₂O ≡ 18mol of H₂

Now, as n=0.5 mol (calculated above)

∴ 0.5mol of Al₂(SO₄)₃ ≡ (0.5×18)mol of H₂

Therefore, 333g of Al₂(SO₄)₃.18H₂O contains 9 moles of Hydrogen molecules

Now, as 1 mol = 6.02214×10²³ units

∴ 9 mol ≡ 9×6.02214×10²³

⇒333g of Al₂(SO₄)₃.18H₂O contains 5.4199×10²⁴ molecules of Hydrogen