Question 1

The air inside a beach ball is at a temperature of 25°C and a pressure of 1.0 atm. If the ball contains 0.85 mol of air, what is its volume?

Accepted Answer

Using the ideal gas law, PV = nRT, where P = 1.0 atm, n = 0.85 mol, R = 0.0821 L·atm/mol·K, and T = 298 K (25°C + 273), the volume V is approximately 21 L.

Question 2

Which of the following correctly pairs a phase of matter with its description?

Accepted Answer

Particles in the gas phase have higher amounts of energy than in the liquid phase, allowing them to move freely and fill the volume of their container.

Question 3

An insect known as a water strider can walk across the surface of a pond. Which of the following is directly responsible for this insect being able to walk on the surface without sinking?

Accepted Answer

Hydrogen bonding between water molecules creates a high surface tension that allows water striders to walk on the surface of water without sinking.

Question 4

A person left a bottle of distilled water and a bottle of a sugary drink outside overnight. In the morning, one liquid was frozen but the other was not. Which liquid was frozen and why did it freeze?

Accepted Answer

The distilled water froze because pure substances, like distilled water, have a higher freezing point than solutions. The sugary drink is a solution, which means its freezing point is lowered due to the presence of sugar, preventing it from freezing as easily as the distilled water.

Question 5

The pH of four different solutions of common materials is measured. Which of the following lists the solutions in order from most acidic to most basic?

Accepted Answer

Battery acid is highly acidic, typically around pH 0-1. Lemon juice, also acidic, has a pH around 2-3. Blood is slightly alkaline with a pH close to 7.4. Laundry detergent is basic, often having a pH of 9-11. Therefore, the correct order from most acidic to most basic is battery acid, lemon juice, blood, laundry detergent.

Question 6

Which of the following statements explains why the bond in hydrogen chloride (HCl) is polar covalent?

Accepted Answer

The bond in hydrogen chloride (HCl) is polar covalent because chlorine has a higher electronegativity than hydrogen, meaning chlorine attracts the shared electron pair more strongly than hydrogen does, creating a dipole with a partial negative charge on the chlorine atom and a partial positive charge on the hydrogen atom.

Question 7

Which of the following samples of sugar will dissolve fastest in a pitcher of lemonade?

Accepted Answer

Granulated sugar has a larger surface area compared to cubed sugar, allowing it to dissolve faster. Additionally, higher temperatures (20°C) increase the solubility and rate of dissolution compared to lower temperatures (5°C).

Question 8

Which of the following comparisons correctly describes subatomic particles?

Accepted Answer

Neutrons have a neutral charge and are significantly more massive than electrons, making option C correct.

Question 9

Which of the following describes the separation of the components of a mixture?

Accepted Answer

Salt being isolated from seawater through evaporation is a process of separating the components of a mixture, specifically separating the salt from the water. This process does not involve breaking down compounds into elements or chemical reactions to form new substances, but rather the physical separation of substances in a mixture.

Question 10

Which of the following statements accurately describes alpha particles in terms of charge and mass?

Accepted Answer

Alpha particles are positively charged (they consist of two protons and two neutrons, similar to a helium nucleus) and are more massive than beta particles (which are high-energy, high-speed electrons or positrons).

Question 11

Which of the following examples is evidence of a physical change?

Accepted Answer

Melting ice cream is a physical change because it involves a change in state from solid to liquid without altering the chemical composition of the ice cream.

Question 12

Which of the following statements describes properties of most metals?

Accepted Answer

Most metals have high melting and boiling points due to the strong metallic bonds between the atoms.

Question 13

Which of the following is not true of a sample of gas as it is heated in a rigid, closed container?

Accepted Answer

When a gas is heated in a rigid, closed container, the volume of the container does not change, meaning the average distance between molecules remains constant. The increase in temperature causes the molecules to move faster, leading to increased pressure and more frequent collisions, but it does not change the spacing between the molecules in a rigid container.

Question 14

The three main types of nuclear radiation are alpha, beta, and gamma. Which of the following lists these types of radiation from highest penetrating power to lowest penetrating power?

Accepted Answer

Gamma rays have the highest penetrating power, followed by beta particles, and alpha particles have the lowest penetrating power.

Question 15

Which of the following explains why saltwater is considered a mixture?

Accepted Answer

Saltwater is considered a mixture because it consists of water (H2O) and salt (NaCl) that are physically combined. Each substance in saltwater retains its own chemical properties, which is characteristic of a mixture.

Question 16

When stirred in 30°C water, 5 g of powdered potassium bromide, KBr, dissolves faster than 5 g of large crystals of potassium bromide. Which of the following best explains why the powdered KBr dissolves faster?

Accepted Answer

Powdered potassium bromide exposes more surface area to water molecules than large crystals, allowing more water molecules to interact with the solute at once, which speeds up the dissolution process.

Question 17

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

Accepted Answer

Liquid nitrogen becoming nitrogen gas is a physical change because it involves a change in the state of matter (from liquid to gas) without altering the chemical composition of the substance.

Question 18

Which of the following statements describes the elements in family 16 of the periodic table?

Accepted Answer

Elements in family 16, also known as the chalcogens, have six valence electrons.

Question 19

Which of the following describes a particle that contains 36 electrons, 49 neutrons, and 38 protons?

Accepted Answer

The particle has more protons (38) than electrons (36), meaning it has lost 2 electrons, giving it a positive charge of 2+. The mass number is not directly given by the number of neutrons or protons alone but is the sum of both, which is not an option provided.

Question 20

Block X and Block Y have the same mass. Both blocks are placed into a container of pure water. Block X ? oats in the water, and Block Y sinks to the bottom of the container. Which of the following statements is an accurate conclusion from this demonstration?

Accepted Answer

Block Y sinks because it has a greater density than water, which implies it has a smaller volume than Block X if both have the same mass. Block X floats because its larger volume gives it a lower density, allowing it to displace enough water to support its weight.

Quiz 2: Chemistry