Catalase is an enzyme that speeds up the breakdown of hydrogen peroxide in cells. During this reaction oxygen is given off. A scientist designs an experiment to determine how much oxygen is given off when varying concentrations of catalase are used. Identify the independent variable A the concentration of the catalase B the result of the reaction C Type of proxide D the shape of the container

The correct option is A

Explanation:

An independent variable is a variable that is intentionally altered (directly or indirectly) and is not dependent on another variable in the course of an experiment. Unlike the independent variable, the dependent variable depends or is presumed to depend on the altered independent variables.

From the explanation above, it can be deduced that the concentration of the catalase is the independent variable as it was intentionally altered (by using different concentrations) in the course of the experiment. The amount of oxygen given off is the dependent variable here

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.