Question

0.1 mole of compound S will weigh ...... g, (given the molar mass in g mol\(^{-1}\) C = 12, H = 1, O = 16) 

Hint:

To find the weight of a given amount of substance, use the formula: \(\text{Weight} = \text{moles} \times \text{molar mass}\).

Answer 1

Correct Answer: 4.6

To ascertain the mass in grams of 0.1 mole of compound S, the molar mass of compound S must first be computed from its chemical formula. Compound S is identified as C₂H₆O.

Molar mass calculation for C₂H₆O:

• Carbon (C): 2 atoms × 12 g/mol/atom = 24 g/mol
• Hydrogen (H): 6 atoms × 1 g/mol/atom = 6 g/mol
• Oxygen (O): 1 atom × 16 g/mol/atom = 16 g/mol

The sum of these atomic masses yields the molar mass of C₂H₆O:

Molar Mass = 24 g/mol + 6 g/mol + 16 g/mol = 46 g/mol

The mass of 0.1 mole of C₂H₆O is determined using the formula:

Mass = Moles × Molar Mass

Mass of 0.1 mole = 0.1 mole × 46 g/mol = 4.6 g

The computed mass is 4.6 g, aligning exactly with the expected value of 4.6 g.