Question

ethan heard that a person who is having a heart attack should chew an aspirin to thin their blood as they wait for an ambulance. since the aspirin needs to dissolve before it can work, he wonders what factors affect how quickly a substance dissolves. so he decides to design an experiment. he has the following supplies available: tap water, sugar cubes, a spoon, a cup, a stopwatch. using only these supplies, which questions can ethan investigate with an experiment? select all that apply. does a sugar cube dissolve more quickly in oil than in tap water? does a sugar cube dissolve faster in water if the water is stirred with a spoon? does fine salt dissolve faster in tap water than coarse salt does? does crushing a sugar cube make it dissolve faster in tap water?

Explanation:

1. Ethan has tap - water, sugar cubes, a spoon, a cup and a stopwatch. He can use the cup to hold water, the spoon to stir, the stopwatch to time the dissolving process.
2. For the question about sugar cube dissolving in oil, he doesn't have oil, so he can't test this.
3. He can test if stirring with a spoon affects the dissolving rate of a sugar cube in water by timing the dissolving process with and without stirring.
4. He doesn't have fine salt and coarse salt, so he can't test the comparison between them.
5. He can crush a sugar cube and time its dissolving in water and compare it with an un - crushed sugar cube's dissolving time.

Answer:

• Does a sugar cube dissolve faster in water if the water is stirred with a spoon?
• Does crushing a sugar cube make it dissolve faster in tap water?