Q. 23

# (a) Calculate the number of moles in 112 g of iron.

(b) Calculate the mass of 0.5 mole of sugar (C_{12}H_{22}O_{11}).

[Atomic mass of Fe = 56 u, C = 12 u, H = 1 u, O = 16 u]

Answer :

(a) Given mass: 112g

Molar mass of iron (Fe) = 56 g/mol

To calculate the number of moles, we will apply the formula given below:

Number of moles = 2

Thus, the number of moles in 112 g of iron is 2

(b) Given: Number of moles = 0.5

Molar mass of C_{12}H_{22}O_{11} = 12 × atomic mass of C + 22 × atomic mass of H + 11 × atomic mass of O

= 12 × 12 + 22 × 1 u + 11 × 16 u = 342 u or 342 g/mol

Now, to calculate mass, apply the formula:

We can write:

Mass(m) = Number of moles (n) × Molar mass of C_{12}H_{22}O_{11} (M)

Mass = 0.5 mol × 342g/mol

Mass = 171g

Thus, the mass of 0.5 mole of sugar (C_{12}H_{22}O_{11}) is 171g.

Rate this question :

(a) Calculate the number of moles in 112 g of iron.

(b) Calculate the mass of 0.5 mole of sugar (C_{12}H_{22}O_{11}).

[Atomic mass of Fe = 56 u, C = 12 u, H = 1 u, O = 16 u]

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