Dallas County Community College

CHEM 1405 introduction to chemistry

Lab: Measurement of mass, length and volume Using Significant Figures
Date: Section: Name:
Pre-lab questions:
1. Measured quantities are associated with specific significant figures based on each
instrument, while exact numbers are different. Underline the exact number/s from the
following:
A) 361 miles B) 12 roses C) 9.28 g D) 5 books E) 0.035 kg
2. When the display on a balance shows 35.300 g, which of the mass should be recorded for
5 significant numbers?
A) 35.3 g B) 35.30 g C) 35.300 g D)0.03530 kg
3. When the length of a metal bar is measured as 49.732 cm, the estimated digit on the
measurement is:
A) 4 B) 9 C) 7 D) 3 E) 2
4. When we need to measure accurate volume of a liquid reagent, we will use volumetric
flasks, burets and pipets; why one cannot use a beaker or Erlenmeyer flask?
The beaker and flask should not be used because they measure to only 1ml and this is not
a precise enough measurement.