Q: Evaluate the expression , paying attention to significant figures.

Background

Topic: Significant Figures in Arithmetic Operations

This question tests your ability to perform arithmetic operations (addition, subtraction, multiplication, division) while correctly applying the rules for significant figures. In chemistry, it is important to report results with the correct number of significant digits based on the precision of the measurements used.

Key Terms and Formulas:

• Significant Figures: The digits in a measurement that are known with certainty plus one digit that is estimated.

• Multiplication/Division Rule: The result should have the same number of significant figures as the measurement with the fewest significant figures.

• Addition/Subtraction Rule: The result should have the same number of decimal places as the measurement with the fewest decimal places.

Step-by-Step Guidance

1. Start by evaluating the subtraction inside the first set of parentheses: . Remember to apply the addition/subtraction rule for significant figures.

2. Multiply the result by . Use the multiplication rule for significant figures.

3. Next, evaluate the division inside the second set of parentheses: . Apply the multiplication/division rule for significant figures.

4. Calculate the subtraction . Again, use the addition/subtraction rule for significant figures.

5. Multiply the result from step 3 by the result from step 4.

6. Add the two products from steps 2 and 5. Make sure to round the final answer to the correct number of significant figures based on the rules for addition.

Try solving on your own before revealing the answer!