Question

A student wonders if adding salt to fresh water will change the temperature at which the water boils. In her kitchen, she puts 1L of fresh water into 2 pans (one pan is large, the other is small), then adds 50 grams of salt to the water in the small pan. She places both pans on the stove, uses a thermometer to obtain their starting temperatures and then turns both heating elements to the same high temperature. She continues to monitor the water temperatures in both pans of water until they both boil. Identify the following parts of the experimental design process.

Answer 1

Hypothesis: Adding salt to fresh water will cause the water to boil at a higher temperature.

Independent Variable: The amount of salt added to the water.

Dependent Variable: The temperature at which the water boils.

Control Group: The pan with fresh water only, without salt added.

Experimental Group: The pan with salt added to the water.

Procedure: Put 1L of fresh water into two pans, add 50 grams of salt to only one of the pans, place both pans on the stove and set the heating elements to the same temperature, and monitor the water temperatures until both pans boil.