Mass and Matter 18 Activity Does the mass of an ice cube change when it melts?
1. Place some ice cubes in a beaker, cover with a clock glass and record the combined mass of the beaker, clock glass and the ice cubes.
2. Wait for the ice cubes to melt and measure the combined mass of the melted ice cubes, beaker and clock glass.
Fig. 17 To test if the mass of an ice cube changes when it melts. Question
Has melting the ice cubes affected the mass? Activity
Does the mass of two chemicals change when they react with each other?
A. Iron sulfate solution and sodium hydroxide solution Method 1. Get two small beakers. 2. Place iron sulfate solution in one beaker and sodium hydroxide solution in the other.
3. Place both beakers and their contents on the electronic balance as shown in Fig. 18 and note their mass.
4. Remove the beakers from the balance and add the iron sulfate solution into the sodium hydroxide solution.
5. Place both of the beakers back on the electronic balance and note their mass.
Questions 1. What did you notice that might indicate a chemical reaction has taken place?
2. Has the chemical change affected the overall mass?
B. Calcium carbonate and hydrochloric acid Repeat the above experiment, using calcium carbonate and hydrochloric acid. Questions 1. What are your observations this time? 2. Has the chemical change affected the overall mass? 3. Can you suggest a reason for any changes?
Fig. 18 Measuring the mass of iron sulfate solution and sodium hydroxide solution.