Experiment One

Physical and Chemical Changes

Procedural Tips

FAQs

Introduction/Goals

Background

Pre-lab

Additional Problems

Supplies and Chemicals

Safety Precautions

Waste Disposal Instructions

Chem 106 Lab Homepage


In this experiment you will
• Produce changes in various substances
• Classify these changes as physical or chemical
 

Print a copy of the Grading Sheet for this lab.

PROCEDURAL TIPS:

 

Evidence of Chemical Reactions

 

FAQ:

Why do I have to wear safety goggles?

 

INTRODUCTION:

Introduction:

In this experiment, we will observe reactions that compounds undergo and determine whether a chemical or physical change has occurred. Observations that indicate a chemical reaction has occurred include such changes as a change in color, the formation of a solid or the formation of a gas.

Goals:

bulletDistinguish physical and chemical changes

Background:

When a substance undergoes a chemical change, a new substance is produced. The new substance will have a different composition and also different properties than the original substance. These changes take place as the result of a chemical reaction. Observations that indicate a chemical reaction has occurred include such changes as a change in color, the formation of a solid or the formation of a gas.

In a physical change, the substance is not altered. Only its appearance is changed. No new substance has been formed. For example, when we melt ice to liquid water a physical change occurs. We still have the same substance - H2O- but the physical appearance has changed.

 

Pre-lab

Read the introductory material on the webpage.

Read Experiment One in the laboratory manual.

Answer the pre-lab study questions on for Experiment One.

You are encouraged to do the Application Questions at the end of Experiment One before coming to lab.

 

Additional Problems:

bulletTrue or False
bulletWhen a substance undergoes a chemical change, its physical state is also changed
bulletIf a chemical change occurs, two or more new substances must be produced.
bulletGive two indications that the burning of a match is a chemical change.
bulletAnswer Problem 1.6 on page 5 of the McMurray textbook and 1.19 on page 14 of the McMurray textbook.

Supplies and Chemicals

bullet CuCO3
bullet6 M HCl
bullet iodine crystals
bulletmethylene chloride
bulletNH4CO3
bulletFeCl3
bullet6M HNO3
bullet0.1 M AgNO3
bullet0.1 M KCN
bulletNaCl
bullet Na2CO3
bullet 0.1 M Ca(NO3)2
bullet Mg metal
bullettest tubes
bulletbunsen burner
bullet100 mL beaker
bulletwatch glass
bulletlimus paper
bulletwire loop

Safety Precautions

SAFETY GOGGLES MUST BE WORN AT ALL TIMES DURING THE LAB.

HCl and HNO3 are acids and may cause burns. If you get any on your skin, rinse thoroughly with water for 10 minutes.               

Methylene chloride is flammable. Do not use around open flames.

AgNO3 may turn your skin brown.

Do not look directly at the burning magnesium metal.

Never point the mouth of the test tube towards anyone while you are heating chemicals.

Waste Disposal Instructions:

Dispose of all solid waste in the wastebasket.

Dispose of all copper waste in the appropriately labeled waste container found under the hood.

Dispose of the methylene chloride in the container labeled for organic solvent waste found under the hood.