Chemistry

Which of the following is an example of an element?

• water (H2O)

• sugar (C12H22O11)

• bromine gas (Br2)

• salt (NaCl)

Consider three different elements A, B, and C. A and B are both non-metals, and C is a metal. How will you classify the substance produced when A and B are chemically combined?

• element

• compound

• homogeneous mixture

• heterogeneous mixture

What type of substance is sample A?

Ø Sample A: When you shine a light through this sample, it scatters the light, making the beam visible. It does not settle upon standing but remains uniformly cloudy.

• element

• compound

• solution

• colloid

What type of substance is sample C?

Ø Sample C: When you dissolve this sample in water, it forms a clear and homogeneous mixture. However, when you add a few drops of silver nitrate (AgNO3) solution to it, it forms a white solid substance.

• element

• compound

• solution

• colloid

What type of substance is sample E?

Ø Sample E: This sample appears as a shiny, metallic solid. When you perform a conductivity test, it conducts electricity well.

• element

• compound

• solution

• colloid

Which of the following statements BEST describes a similarity between pure substances and solutions?

• Both are heterogeneous mixtures.

• Both consist of two or more different substances mixed.

• Both can be broken down by physical processes.

• Both have a uniform composition throughout the mixture.

Eunice is fond of reading Harry Potter books. She measured the dimensions of the book to be 9.0 inches long, 6.2 inches wide, and 1.7 inches thick. How much volume does this book have?

• 93 in3

• 94 in3

• 95 in3

• 96 in3

During PE class, the nursing students measure their height in centimeters and mass in grams. What would the nursing students do if their PE teacher asks them to report their mass in pounds? (1 lb = 454 g)

• Add it with 454 units.

• Subtract it with 454 units.

• Multiply it with 454 units.

• Divide it with 454 units.

Denisse is conducting an experiment to study the effect of temperature on the solubility of a substance. Which of the following statements is CORRECT?

• Solubility decreases with temperature for most solids.

• Solubility increases with temperature for most solids.

• Solubility of gases in liquids increases with temperature.

• Solubility of gases in liquids is not affected by temperature changes.

Before administering an antibiotic, Eloisa mixes the powdered medicine with sterile water and swirls the vial. What action increases the rate of dissolution?

• Changing the solvent’s polarity.

• Increasing the pressure inside the vial.

• Agitating the solution.

• Reducing the surface area of the solute.