All AP Chemistry Resources
Example Questions
Example Question #43 : Laboratory Techniques And Analysis
You are trying to create a new chemical structure. You need exactly 9mL of phenyllithium for your next reaction. Which measuring tool would be the most accurate to measure out that liquid?
10mL graduated cylinder
10mL syringe
9mL watch glass
100mL beaker
9mL volumetric pipet
9mL volumetric pipet
When measuring any liquid in the lab, a volumetric pipet or flask is always going to be the most accurate. This makes the 9mL volumetric pipet the best choice.
There is no such thing as a 9mL watch glass. Though a 10mL syringe and graduated cylinder would be quite accurate, the 9mL volumetric pipet is more accurate, and remember the question asked for the best out of the answer choices. A beaker is very inaccurate and should only be used to transfer solutions, not to measure them.
Example Question #44 : Laboratory Techniques And Analysis
An experiment calls for you to titrate a solution of with a solution of of unknown concentration. The solution of is held in an Erlenmeyer flask. What piece of laboratory equipment should you use to administer the solution?
Graduated cylinder
Volumetric pipet
Watch glass and spatula
Buret
Buret
In a titration, you should use a buret to administer the solution into the solution. A buret gives you the most accuracy in running the titration as you can dispense the solution drops at a time. The buret will also allow you to accurately determine the volume of needed to complete the titration. A watch glass and spatula would be inappropriate for this situation because you are dealing with liquids. Pouring from a graduate cylinder would not be accurate enough and the titration results would be subject to lots of error. A volumetric pipet will not allow you to keep track of the volume needed to complete the titration.
Example Question #45 : Laboratory Techniques And Analysis
An experiment calls for measuring of a solution in a graduated cylinder. How should the graduated cylinder be read?
Hold the graduated cylinder so the meniscus is slightly below eye level, then make sure the bottom of the meniscus is at
Hold the graduated cylinder so the meniscus is slightly above eye level, then make sure the bottom of the meniscus is at
Hold the graduated cylinder so the meniscus is at eye level, then make sure the bottom of the meniscus is at
Crouch down until your head is on the same level as the table top, then look to make sure the bottom of the meniscus is at
Hold the graduated cylinder so the meniscus is at eye level, then make sure the bottom of the meniscus is at
In order for an accurate reading of a graduated cylinder, hold the graduated cylinder at eye level then make sure the bottom of the meniscus is at the desired volume. Having the graduated cylinder slightly below eye level will result in readings that are higher than they are supposed to be. Having the graduated cylinder slightly above eye level will result in readings that are lower than they are supposed to be. Never place your head on the same level as the table to read a graduated cylinder. If the graduated cylinder tips over for any reason, you will splash the solution held within on your face.
Example Question #1 : Laboratory Equipment
While conducting an experiment, you need to measure exactly of a sulfuric acid solution. Which piece of equipment should you use?
beaker
volumetric pipette
Graduated cylinder
Mohr pipette
volumetric pipette
A volumetric pipette is made to dispense a specific amount of liquid very accurately. The Mohr pipette, beaker, and graduate cylinder will not measure a specific amount of liquid as accurately as the volumetric pipette.
Example Question #47 : Laboratory Techniques And Analysis
While conducting an experiment, you are required to measure out exactly of potassium hydrogen phthalate. What should you use to measure out the correct amount?
Erlenmeyer flask
Triple beam balance
Centigram balance
Analytical balance
Analytical balance
Potassium hydrogen phthalate is a solid at room temperature, so we can use a balance and a weigh boat or weigh paper. When measuring precise amounts of chemicals, an analytical balance will be able to provide the most accurate reading of mass.
Example Question #48 : Laboratory Techniques And Analysis
For an experiment, you are required to heat a sample of a solid to very high temperatures. What piece of laboratory equipment should you use to heat the solid?
Crucible
Beaker
Erlenmeyer flask
Test tube
Crucible
When you need to heat anything up to high temperatures, you must use a crucible. Glassware is not able to withstand as much heat as a crucible.
Example Question #49 : Laboratory Techniques And Analysis
An experiment requires you to mix a solution of with a solution of and then observe the reaction. What should the solutions be mixed in?
A volumetric pipet
A graduated cylinder
A buret
A beaker
A beaker
A beaker is the best choice for mixing these two solutions. Graduated cylinders, burets, and pipets are all used to measure specific amounts of solution. Also, stirbars can be easily added to beakers to facilitate the reaction.
Example Question #50 : Laboratory Techniques And Analysis
You are required to find the absorbance of a specific solution. What piece of equipment should you use?
Spectrophotometer
Analytical balance
Chromatography paper
Litmus paper
Spectrophotometer
A spectrophotometer should be used because it is used to measure absorbance at specific wavelengths. An analytical balance is used for measuring mass. Chromatography paper is used to separate different pigments found in a chemical. Litmus paper is used to determine the pH of a substance.
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