Calculate the number of moles:(i) 5.0 L of 0.75 M Na2CO3 (ii) 7.85 g

1.	Calculate the number of moles:(i) 5.0 L of 0.75 M Na2CO3 (ii) 7.85 g of Fe (iii) 34.2 g of sucrose (C12H22O11)
Answer» (i) Number of moles of Na₂CO₃ = Molarity × Volume of solution in litre = 0.75 × 5 = 3.75 mol (ii) Number of moles of Fe = \(\frac{Mass}{Molecular\,mass}\) =\(\frac{7.85}{56}\) = 0.14 (iii) Number of moles of sucrose = \(\frac{Mass}{Molecular\,mass}\) = \(\frac{34.2}{34.2}\) = 0.1

Calculate the number of moles:(i) 5.0 L of 0.75 M Na2CO3 (ii) 7.85 g of Fe (iii) 34.2 g of sucrose (C12H22O11)

Answer»

(i) Number of moles of Na₂CO₃

= Molarity × Volume of solution in litre

= 0.75 × 5

= 3.75 mol

(ii) Number of moles of Fe

= \(\frac{Mass}{Molecular\,mass}\)

=\(\frac{7.85}{56}\)

= 0.14

(iii) Number of moles of sucrose

= \(\frac{Mass}{Molecular\,mass}\)

= \(\frac{34.2}{34.2}\)

= 0.1