ScienceSource.ca Dry Lab Activity

Unit B - Chapter 4

Investigating Science 9

Inquiry Activity

Where's the Evidence

Skills Reference 2

Skills you Will Use

  • Using appropriate equipment and tools
  • Drawing conclusions

Safety

  • Apron
  • Goggles

Caution

In this lab you will be dealing several chemicals that can irritate your skin. Take all precautions to prevent contact with these chemicals.

Use goggles to protect your eyes and an apron to protect your clothes.

A chemical change always results in the formation of a new substance. A chemical reaction is a process in which a chemical change occurs. However, it may not always be obvious when a chemical reaction has occurred.

In this activity, you will investigate several supposed reactions and determine whether a chemical change has taken place.


Question

What are some signs that a chemical reaction has taken place?


Materials and Equipment

  • 4 small plastic cups
  • two plastic spoons
  • tongs
  • matches
  • 10 ml graduated cyclinder
  • 10cm square sheet of aluminum foil
  • birthday candles
  • sugar
  • clay
  • dilute hydrochloric acid (HCl) in a dropper bottle
  • sodium carbonate powder
  • copper sulfate solution
  • sodium carbonate solution

Dry Lab

A "dry lab" activity includes collected data and/or a video solution for your convenience. You can simply watch the following video and use the provided data, or if you wish to perform this lab for yourself, follow the procedure steps 1 through 16 described in the video. The same steps are included in written form in the documents available for download on the bottom of this page.



Analyzing and Interpreting

  1. What do your observations tell you about the supposed chemical reactions? Did a chemical reaction occur in each case? Explain your answers.

Forming Conclusions

  1. A student performing the procedure steps 1 through 16 recorded the following observations and results. What do these results indicate about the three supposed chemical reactions - did a chemical change occur in each case? Explain your answers.

    Reaction

    Observations and Results

    Sodium carbonate powder + HCl

    Fizzed during reaction, produced bubbles of gas

    Sugar

    Sugar slowly melts, then turned into a dark black substance, gas given off, reaction produced a sweet smell.

    Copper sulfate + sodium carbonate solution

    Produced a greenish solid precipitate



  2. When sugar is heat gradually, it first melts, but then begins to change colour while giving off a sweet odour, eventually turning completely black. At what exact point would you say a chemical reaction began to take place? Explain your answer.