A chemistry student records these masses: • Empty beaker: 123.8 g • Beaker + dry…
PHYSICS · Subjective · CBSE · Physics · Units and Measurements · Units and Measurements
Problem
A chemistry student records these masses:
• Empty beaker: 123.8 g
• Beaker + dry sand: 175.32 g
• Beaker + water: 163.246 g
(a) Determine the mass of dry sand placed in the beaker and state the value to the proper precision.
(b) Determine the mass of water added and state the value to the proper precision.
(c) The student mistakenly believes that subtracting the two masses obtained in (a) and (b) will give the mass difference to three decimal places. Perform the subtraction correctly and justify the number of decimal places retained.
(d) Explain briefly why the least‐precise measurement, and not the most precise one, dictates the final precision in parts (a)–(c).