CHEM 109L Laboratory Safety, Measurement, and Academic Integrity Study Guide

Laboratory Safety Rules

General Safety Guidelines

Laboratory safety is essential for accident-free operations in chemistry labs. Adhering to safety rules protects students and staff from chemical hazards and physical injuries.

• Wear safety goggles at all times in the laboratory. Never wear contact lenses in the lab, as chemicals can become trapped and cause eye damage.

• Horseplay is strictly prohibited to prevent accidents.

• Unsupervised work is forbidden. Always work under supervision.

• Report all accidents immediately to your instructor.

• Know the location of safety equipment such as fire extinguishers, eyewash stations, and safety showers.

• Handle chemicals with respect. Be familiar with their properties and hazards before use.

• Handle glassware with care to avoid breakage and injury.

• Wear proper clothing; bare feet and open-toed shoes are not permitted.

• Never light a flame until you are sure there are no flammable materials nearby. No smoking is permitted.

• Neatness reduces accidents. Clean up spilled chemicals, broken glass, and floods immediately.

• Think! A conscientious and scholarly attitude is the best defense against laboratory accidents.

Additional info: Students must supply a lab coat, safety goggles, a bound notebook, and a calculator for each session.

Academic Integrity

Expectations and Policies

Academic integrity is fundamental in all aspects of student work, including examinations, laboratory work, reports, and logs. Plagiarism and cheating are strictly prohibited.

• Plagiarism is presenting someone else's words or ideas as your own, whether from print or electronic sources.

• Copying reports, in whole or part, is considered gross scientific and academic dishonesty.

• The instructor has the right to use electronic devices to detect plagiarism.

• Students are responsible for reading the university's full plagiarism policy.

Additional info: Academic dishonesty may result in a failing grade and disciplinary action.

General Laboratory Instructions

Laboratory Notebook Requirements

A bound laboratory notebook is required for recording all experimental work. Entries must be made in ink, and each experiment should start on a new page.

• Include the following before each session:

  • Title of experiment

  • Purpose of experiment

  • List of materials

  • Brief outline of procedure

  • Blank data tables

  • Any calculations/observations performed before lab

• Record detailed observations and data during the experiment.

• Complete all calculations and draw graphs as required after the experiment.

• Discussion of results should be included in the notebook.

Basic Measurement Techniques

Introduction to SI Units and Metric Prefixes

The International System of Measurement (SI) is the global standard for scientific measurement. It uses base units and prefixes to express quantities.

• Base units include meter (length), gram (mass), liter (volume), and degree Celsius/Kelvin (temperature).

• Metric prefixes allow for easy conversion between units:

Prefix	Abbreviation	Multiplier
mega-	M	× 1,000,000
kilo-	k	× 1,000
centi-	c	× 0.01
milli-	m	× 0.001

Estimating and Uncertainty in Measurement

All scientific measurements include some uncertainty. The last digit in a measurement is the estimated digit, representing the uncertainty.

• When using analog devices, estimate the last significant figure.

• Report digits you are certain about plus one additional digit you estimate.

Measuring Device	Uncertainty
10 mL graduated cylinder	± 0.01 mL
50 mL graduated cylinder	± 0.1 mL
50 mL buret	± 0.05 mL

Example: If you measure 25.36 mL in a buret, the uncertainty is ±0.05 mL, so the true value is between 25.31 mL and 25.41 mL.

Density and Specific Gravity

Definitions and Calculations

Density is the mass per unit volume of a substance. Specific gravity is the ratio of the density of a substance to the density of water.

• Density formula:

$\text{Density} = \frac{\text{Mass}}{\text{Volume}}$

• Specific gravity formula:

$\text{Specific Gravity} = \frac{\text{Density of substance}}{\text{Density of water}}$

Example: If a liquid has a mass of 25 g and a volume of 20 mL, its density is $\frac{25\,\text{g}}{20\,\text{mL}} = 1.25\,\text{g/mL}$.

Appendices Overview

Laboratory Equipment and Techniques

The appendices provide reference material on the use of volumetric glassware, common laboratory equipment, and techniques for accurate measurement.

• Volumetric glassware includes pipettes, burets, and graduated cylinders for precise liquid measurement.

• Common equipment includes balances, thermometers, and safety apparatus.

Additional info: Proper use and calibration of equipment are essential for reliable experimental results.

Summary Table: Key Laboratory Safety Equipment

Equipment	Purpose
Safety Goggles	Protect eyes from chemical splashes
Lab Coat	Protect skin and clothing
Eyewash Station	Flush eyes in case of chemical exposure
Fire Extinguisher	Put out small fires
Safety Shower	Rinse chemicals from body

Conclusion

Understanding and following laboratory safety rules, maintaining academic integrity, and mastering basic measurement techniques are foundational skills for success in GOB Chemistry laboratory courses. Always consult your instructor and laboratory manual for specific procedures and requirements.