A scientist needs to pour exactly 20 mL of acetic acid into six different beakers. Which of the following instruments would best help the scientists to accurately distribute the acid?

A. Erlenmeyer flask
Incorrect. Erlenmeyer flask is used to heat and store liquids or solids that may produce gases during a reaction, or may splatter when heated or stirred.

B. Beaker
Incorrect. Beakers hold solids or liquids that will NOT release gases during a reaction, and/or that are unlikely to splatter when heated.

C. Graduated cylinder
Correct! Graduated cylinders are used to measure volumes of a liquid.

D. Funnel
Incorrect. A funnel is used to help transfer liquid from one container to another.

In order to complete a lab experiment the student needs to add one drop of a liquid to a solution. Which piece of equipment will best aid the student in completing this lab activity?

A. Forceps
Incorrect. Forceps are used to pick up small objects.

B. Pipette
Correct! The pipette moves small amount of liquid from one container to another.

C. Volumetric flask
Incorrect. Volumetric flasks measure one specific volume and can be used to make up solutions to a known volume.

D. Crucible
Incorrect. Crucibles are used to heat solids to very high temperatures.

A student hypothesizes that 10-grams of salt will dissolve faster in 40°C water than it will in 20°C water. The student has already gathered a hot plate, some beakers, and some heat resistant gloves. What other equipment will be needed to test the students’ hypothesis?

A. Thermometer, stopwatch, balance
Correct!

B. Test tube, barometer, thermometer
Incorrect.

C. Erlenmeyer flask, stopwatch, hand lens
Incorrect.

D. Burette, balance, stir rod
Incorrect.

Lab Procedures:

  1. Place 10 g of baking soda in a Ziploc bag
  2. Place 20mL of vinegar into a film canister and snap the lid closed
  3. Place the film canister in the bag. Seal the bag. Make sure to get all the excess air out of the Ziploc bag.
  4. Measure and record the mass of the bag and its contents.
  5. While the bag remains closed, take the lid off the film canister. Allow the baking soda and the vinegar to mix.
  6. When the reaction is complete; re-measure the mass of the bag and its contents.

In order for a student to conduct the lab listed above, which list of equipment below will be needed?

A. Ruler, thermometer, beaker
Incorrect.

B. Graduated cylinder, hot plate, stopwatch
Incorrect.

C. Erlenmeyer flask, pipette, beaker
Incorrect.

D. Safety goggles, graduated cylinder, electronic balance
Correct!