Question

​calculate no of moles in 392g of sulphuric acid and 9g of aluminium

Answer 1

we know the formula to calculate no of moles

no of moles= given mass /molecular mass

Here molecular mass of Sulphuric acid is 98 amu
therefore no moles of sulphuric acid =392/98=4 moles

and the atomic mass of Aluminum is 27 amu
therefore no of moles of aluminum= 9/27=0.3 moles

Hope this helped u :-)

Answer 2

"4 moles are present in 392 g of sulphuric acid and 3 moles are present in 9 g of Aluminium.

Number of moles per litre solution is called molarity.

$Molarity\quad =\quad \frac { { Number\quad of\quad moles } }{ 1{ L\quad solution } }$

One mole of solution contains Avogadro's number of molecule. Avogadro's number is equal to $6.023 \times 10^{23}$ molecules

Number of moles in 392 g of sulphuric acid:

Molar mass of $H_{2} S O_{4} = 98 g/mol$

$Number\quad of\quad moles\quad =\frac { { Given\quad mass } }{ { Molar\quad mass } }$

$=\frac { 392 }{ 98 }$

$Number\quad of\quad moles\quad =\quad 4$

Therefore, 4 moles are present in 392 g of sulphuric acid.

Number of moles in 9 g of aluminium:

Molar mass of Aluminium = 27 g/mol

$Number\quad of\quad moles\quad =\frac { { Given\quad mass } }{ { Molar\quad mass } }$

$=\frac { 27 }{ 9 }$

$Number\quad of\quad moles\quad =\quad 3$

Therefore, 3 moles are present in 9 g of Aluminium."