Evaluate the mathematical expression and report the exact number of significant figures the final an — Mole Concept and Some Basic Concepts of Chemistry Chemistry Question
Question
Evaluate the mathematical expression $\frac{(12.42 - 12.10) \times 4.15}{0.0050}$ and report the exact number of significant figures the final answer must contain according to strict error propagation rules.
💡 Solution & Explanation
Step 1: Subtraction in the numerator: $12.42 - 12.10 = 0.32$. The result $0.32$ is limited to two decimal places (addition/subtraction rule) and has 2 significant figures. Step 2: Multiplication/division: $(0.32 \times 4.15) / 0.0050$. Here, $0.32$ has 2 sig figs, $4.15$ has 3 sig figs, and $0.0050$ has 2 sig figs. The multiplication/division rule dictates the final answer must have the lowest number of sig figs among the inputs, which is 2.