FREE Master of Chemistry: Physical Chemistry Questions and Answers

Question 1

It is referred to as the solute concentration per unit volume.

Accepted Answer

concentration

Answer

Concentration is a general quantitative term used to express the amount of solute present in a given amount of solvent or total solution. It quantifies how much of a substance is dissolved or dispersed in another substance, typically expressed as mass per unit volume or moles per unit volume. While ppm and molality are specific units of concentration, 'concentration' is the overarching concept.

Question 2

if 2g of NaCl is dissolved in 20g of water, then the solution's percentage is

Accepted Answer

9%

Answer

To calculate the percentage concentration (mass/mass), we use the formula: (mass of solute / total mass of solution) * 100%. Here, the mass of solute (NaCl) is 2g, and the mass of solvent (water) is 20g. The total mass of the solution is 2g + 20g = 22g. Therefore, the percentage is (2g / 22g) * 100% ≈ 9.09%, which rounds to 9%.

Question 3

Choose the inaccurate composition percentage expression.

Accepted Answer

m/d%

Answer

Common composition percentage expressions include mass/mass (m/m%), mass/volume (m/v%), and volume/volume (v/v%). These units clearly define the components being measured. The expression 'm/d%' is not a standard or recognized unit for expressing composition percentage in chemistry, making it the inaccurate option.

Question 4

Pa is the SI unit for pressure. equivalent to

Accepted Answer

1N/m²

Answer

Pressure is fundamentally defined as force applied per unit area. In the International System of Units (SI), the unit for force is the Newton (N), and the unit for area is the square meter (m²). Therefore, one Pascal (Pa), the SI unit for pressure, is equivalent to one Newton per square meter (1 N/m²).

Question 5

Which one compresses more easily?

Accepted Answer

gas

Answer

Gases are the most compressible state of matter because their particles are widely spaced and experience very weak intermolecular forces. This allows them to be forced into a much smaller volume under pressure. Solids and liquids have particles that are already closely packed, making them significantly less compressible.

MChem Master of Chemistry Practice Test

MChem Master of Chemistry Practice Test

FREE Master of Chemistry: Physical Chemistry Questions and Answers