Question

Arun and Marcus are asked to compare the solubility of two salts in water at room temperature. The two salts are labelled X and Y

1) name the independent variable in the investigation
2) name the dependent variable in the investigation
3) list the control variables in the investigation

Answer 1

In the investigation, the independent variable is the type of salt (X or Y), the dependent variable is the solubility of the salts in water, and control variables could include the temperature of the water, the amount of water, the size of the salt crystals, and the amount of salt used.

Step-by-step explanation:

In the investigation to compare the solubility of two salts labeled X and Y in water at room temperature:

• The independent variable is the type of salt (X or Y). This is because it is the variable that is changed or controlled in the experiment to test its effect on the dependent variable.
• The dependent variable is the solubility of the salts in water. This is what is being measured or observed in the experiment.
• The control variables could include the temperature of the water, the amount of water, the size of the salt crystals, the stirring rate, the purity of the water, and the amount of salt used. These are kept constant to ensure that any difference in the solubility of the two salts is due to the type of salt itself and not other external factors.

For example, if an experiment were conducted to test the growth of algae with and without the addition of phosphate, the independent variable would be the presence or absence of phosphate, the dependent variable would be the amount of algal growth, and the control variables might include the volume of water in each tank and the type of algae used.

Answer 2

1) Salts X and Y

2) The solubility of the salts

3) a) The solvent

b) The solvent temperature

Step-by-step explanation:

1) The independent variable is the variable that is suspected to be the cause of the subject of the investigation

The given investigation is meant to investigate the solubility of different salts

Therefore, the solubility is expected to be dependent on the type of salt, and the independent variable is the type of salt, X or Y

2) The dependent variable is the effect meant to be observed in the investigation, which is the solubility of the salt in water at room temperature

3) The control variables are the variables which are held constant during the investigation, including;

a) The solvent used if the investigation; water

b) The temperature of the solvent; Room temperature