Concept:Mole calculations require the mass to be inputted in grams. Therefore, kilogram values must be converted to grams before division by molar mass.
Formula:$$ n = \frac{m \text{ (in grams)}}{M} $$
Solution:- First, determine the molar mass of Calcium Carbonate (\( \text{CaCO}_3 \)):
- \( M = 40 + 12 + (3 \times 16) = 40 + 12 + 48 = 100 \text{ g/mol} \).
- Convert the given mass to grams: \( 1.75 \text{ kg} = 1.75 \times 1000 = 1750 \text{ grams} \).
- Calculate moles: \( n = 1750 \text{ g} / 100 \text{ g/mol} = 17.5 \text{ moles} \).
Why other options are incorrect:- 0.0175 mol: Results from erroneously dividing the kilogram mass directly by molar mass (1.75 / 100).
- 1.75 mol: Results from a simple magnitude assumption error.
- 1750 mol: Forgets to divide by the molar mass (100) after converting to grams.
Quality & Fidelity Assurance:
Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.