Common Lab Equipment & Techniques Cheat Sheet

Key Facts

• Density is calculated with $\rho = \frac{m}{V}$, where $\rho$ is density, $m$ is mass, and $V$ is volume.
• For dilutions, use $M_1V_1 = M_2V_2$, where $M_1$ and $V_1$ describe the starting solution and $M_2$ and $V_2$ describe the diluted solution.
• Percent error is calculated with $\%\text{ error} = \left|\frac{\text{experimental} - \text{accepted}}{\text{accepted}}\right| \times 100\%$.
• Percent yield is calculated with $\%\text{ yield} = \frac{\text{actual yield}}{\text{theoretical yield}} \times 100\%$.
• A graduated cylinder is usually more accurate for measuring liquid volume than a beaker because it has narrower markings.
• Read the bottom of the meniscus at eye level when measuring most clear liquids in a graduated cylinder or burette.
• Always record a measurement with the correct unit and the proper number of significant figures for the instrument.
• Use a fume hood for volatile, toxic, or strongly irritating chemicals because it pulls hazardous vapors away from the workspace.

Vocabulary

Beaker

A wide-mouthed container used for mixing, heating, and holding liquids, but not for highly precise volume measurements.

Graduated Cylinder

A tall, narrow container with volume markings used to measure liquid volume more accurately than a beaker.

Burette

A long, marked glass tube with a stopcock used to deliver precise volumes of liquid, especially during titrations.

Meniscus

The curved surface of a liquid in a container that must be read at eye level for accurate volume measurement.

Tare

To reset a balance to $0$ with a container on it so the balance measures only the mass of the sample.

Filtration

A separation technique that uses a filter to separate an insoluble solid from a liquid.