chem 103 lab exam 1 spring 2021-2022 best practice exam material
1. Three students measured their liquid samples using different laboratory equipment and
received the following results: 45.26 μL, 324.52 mL and 0.0128 L. Following rules of
significant figures their total combined volume in mL should be reported as: [5]
337 mL (give only final result of addition)
2. Complete the following calculation and report your answer to the correct number of significant
figures: [5]
146 / (2.62 – 2.58) = 3,650
3. Student titrated a sample and used 24.00 mL of the titrant. What volume of the titrant he
should use for calculations when expressing it in liters? Click, drag and unclick the green circle
over a chosen answer letter) [5]
a) 0.24 L b) 2.40 L c) 0.0024 L d) None. My answer is 0.024 L
4. Four students when weighing two pounds object received their results as given below.
Which student should claim his results as precise and accurate? [5]
a) 32.02 oz 32.00 oz 31.98 oz b) 12.02 oz 12.04 oz 16.05 oz
c) 18.01 oz 18.01 oz 18.02 oz c) 16.01 oz 16.00 oz 15.99 oz
5. A jeweler asked you to check whether the metal he wanted to purchase on a flea market was
indeed at least 18 carat gold (75% gold). You decided to weigh the metal (or alloy) piece and
place it into a graduated cylinder filled partially with water to determine its volume. Then you
determined the mass of the metal (alloy). Here are your results:
Mass of the metal (or alloy) - 14.268 g
Volume of the water in the graduated cylinder - 12.05 mL
Volume of the water + piece of metal (or alloy) in the graduated cylinder - 13.15 mL
Using these data the determined density of the metal (alloy) should be reported as (give unit)
12.97 g/mL^3 [5]
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1. Three students measured their liquid samples using different laboratory equipment and
received the following results: 45.26 μL, 324.52 mL and 0.0128 L. Following rules of
significant figures their total combined volume in mL should be reported as: [5]
337 mL (give only final result of addition)
2. Complete the following calculation and report your answer to the correct number of significant
figures: [5]
146 / (2.62 – 2.58) = 3,650
3. Student titrated a sample and used 24.00 mL of the titrant. What volume of the titrant he
should use for calculations when expressing it in liters? Click, drag and unclick the green circle
over a chosen answer letter) [5]
a) 0.24 L b) 2.40 L c) 0.0024 L d) None. My answer is 0.024 L
4. Four students when weighing two pounds object received their results as given below.
Which student should claim his results as precise and accurate? [5]
a) 32.02 oz 32.00 oz 31.98 oz b) 12.02 oz 12.04 oz 16.05 oz
c) 18.01 oz 18.01 oz 18.02 oz c) 16.01 oz 16.00 oz 15.99 oz
5. A jeweler asked you to check whether the metal he wanted to purchase on a flea market was
indeed at least 18 carat gold (75% gold). You decided to weigh the metal (or alloy) piece and
place it into a graduated cylinder filled partially with water to determine its volume. Then you
determined the mass of the metal (alloy). Here are your results:
Mass of the metal (or alloy) - 14.268 g
Volume of the water in the graduated cylinder - 12.05 mL
Volume of the water + piece of metal (or alloy) in the graduated cylinder - 13.15 mL
Using these data the determined density of the metal (alloy) should be reported as (give unit)
12.97 g/mL^3 [5]
/ 25
