CWEA grade 1 lab analyst practice test part 2
Questions and Answers with Complete Solutions
UPDATED!!!
Measurement Precision and Recording
Question Answer
Where should the precision of From the glassware itself
a measurement come from? (if labeled).
What should you do if no Use the general precision
precision is written on the values provided in the
glassware? lab manual.
Record values to the
How should you record correct number of
volumes and masses in your decimal places based on
notebook? precision (significant
digits).
Example: Measuring 10 mL $10.0\text{ mL}$
with a 10 mL graduated
, 2|Page
Question Answer
cylinder ($\pm 0.1\text{ mL}$),
how should you write it?
Do you need to include the No, as long as the
absolute precision next to your significant digits are
measurement? correct.
Do you need to include the No (e.g., "10 mL
uncertainty in the equipment graduated cylinder" is
name? sufficient).
Equipment Precision Values
Equipment Precision
Burette $\pm 0.01\text{ mL}$
10 mL graduated cylinder $\pm 0.1\text{ mL}$
Precision when subtracting
$\pm 50\%$ of the
two readings from a 10 mL
difference between the lines
graduated cylinder?