UPCAT Reviewer (SCIENCE)

In a solution the substance that does the dissolving is called ______.

• concentration

• solute

• electrolyte

• solvent

Which of the following reasons best describes why water is a good solvent?

• It is a negatively charged ion.

• It repels most molecules.

• It is such a small molecule.

• Due to its polarity and small molecular size.

A solution that cannot hold any more solute at room temperature would be classified as ___________.

• dilute solution

• concentrated solution

• saturated solution

• supersaturated solution

Ethanol dissolved in water is an example of what kind of solution?

• solution between two miscible liquids

• solution between a solid and liquid

• suspension between two liquids

• ethanol and water do not form a solution

To form a supersaturated solution requires ________.

• equal amount of solute and solvent​

• a larger container for the solution

• reducing the amount of solute

• reducing the amount of solvent

Which one of the following is an example of a physical change?

• an iron rusting

• a steak cooking

• a sugar dissolving in water

• a candle burning

Which one of the following is not a physical change?

• clothes drying in the dryer

• making a cup of coffee

• chopping wood

• boiling an egg

What happens to the properties of a substance after a chemical change?

• properties are identical before and after the change

• properties are different before and after the change

• neither of the two statements are correct

• either of the two statements are correct

Heptane is always composed of 84% carbon and 16% hydrogen by mass. What law does this observation illustrate?

• Law of Multiple Proportions

• Law of Definite Proportions

• Law of Conservation of Mass

• Law of Conservation of Energy

Provide the mass number for an atom that has 10 protons, 10 electrons, and 11 neutrons.

• 31

• 20

• 10

• 21