Question 1: The minimum amount of energy required for effective collisions between reacting particles is known as
A) Activation energy B) Bond energy C) Kinetic energy D) Potential energy
Answer: A) Activation energy
Explanation: Activation energy is the minimum amount of energy required for effective collisions between reacting particles to result in a chemical reaction. Option A is the correct answer.
Question 2: The bond formed between H2O and H+ to form the hydroxonium H3O+ is
A) Dative B) Covalent C) Electrovalent D) Ionic
Answer: B) Covalent
Explanation: The bond formed between H2O and H+ to form the hydroxonium H3O+ is a covalent bond, which involves the sharing of electrons between atoms. Option B is the correct answer.
Question 3: An element X forms the following oxides X2O, XO and XO2. This phenomenon illustrates the law of ________.
A) Conservation of mass B) Definite proportion C) Mass action D) Multiple proportion
Answer: D) Multiple proportion
Explanation: The formation of different oxides of an element in multiple proportions illustrates the law of multiple proportion, which states that when two elements form more than one compound, the ratios of the masses of one element that combine with a fixed mass of the other element are in small whole-number ratios. Option D is the correct answer.
Question 4: How many moles of oxygen would contain 1.204 × 1024 molecules?
NB: Avogadro’s constant (NA) = 6.02 × 1023
A) 1 B) 2 C) 3 D) 4
Answer: C) 3
Explanation: To calculate the number of moles of oxygen, we first need to divide the number of molecules by Avogadro’s constant. Thus:
1.204 × 1024 molecules ÷ 6.02 × 1023 molecules/mol = 2 moles
Option C is the correct answer.
Question 5: Which of the following statements about solids is correct?
A) Solid particles are less orderly than those of a liquid B) Solid have lower densities than liquids C) Solid particles have greater kinetic energies than those of liquids D) Solid particles cannot be easily compressed
Related Lesson: Summarizing the Solid State of Matter | Liquids and Solids
Answer: D) Solid particles cannot be easily compressed
Explanation: One of the characteristic properties of solids is that their particles are closely packed together and cannot be easily compressed. Option D is the correct answer.
Question 6: Which of the following apparatus can be used to measure a specific volume of a liquid accurately?
A) Beaker B) Conical flask C) Measuring cylinder D) Pipette
Answer: D) Pipette
Explanation: While all the options can be used to measure the volume of a liquid, a pipette is the most accurate tool for measuring a specific volume of liquid. Pipettes are designed to measure and transfer small and precise volumes of liquid, whereas the other apparatus have a larger margin of error.
Question 7: The spreading of the scent of a flower in a garden is an example of ________.
A) Brownian motion B) Diffusion C) Osmosis D) Tyndall effect
Answer: B) Diffusion
Explanation: Diffusion is the movement of particles from an area of high concentration to an area of low concentration. The spreading of the scent of a flower in a garden is an example of diffusion, as the scent molecules move from the flower to the surrounding air, where the concentration of the scent is lower.
Question 8: Propane and carbon (IV) oxide diffuse at the same rate because [H = 1.00, C = 12.0, O = 16.0]
A) They are both gases B) Their molecules contain carbon C) They have the same relative molecular mass D) Both are denser than air
Answer: C) They have the same relative molecular mass
Explanation: The rate of diffusion of a gas depends on its molecular mass, with lighter gases diffusing more quickly than heavier gases. Propane (C3H8) and carbon dioxide (CO2) have the same relative molecular mass, which means they diffuse at the same rate.
Question 9: Which of the following laws make up the general gas equation PV/T = K? A) Boyle’s and Charles’ laws B) Boyle’s and Graham’s laws C) Charles’ and Graham’s laws D) Dalton’s and Graham’s laws
Answer: A) Boyle’s and Charles’ laws make up the general gas equation PV/T = K.
Explanation: Boyle’s law states that at a constant temperature, the volume of a gas is inversely proportional to its pressure. Charles’ law states that at a constant pressure, the volume of a gas is directly proportional to its temperature. The general gas equation combines these two laws to relate the pressure, volume, and temperature of a gas at any given state. Graham’s law relates to the diffusion of gases, while Dalton’s law relates to the partial pressure of gases in a mixture.
Question 10: What is the energy called that accompanies the addition of an electron to an isolated gaseous atom? A) Atomization B) Electronegativity C) Electron affinity D) Ionization
Answer: C) Electron affinity is the energy that accompanies the addition of an electron to an isolated gaseous atom.
Explanation: Electron affinity is the energy change that occurs when an electron is added to a neutral gaseous atom to form a negatively charged ion. It is a measure of how much the atom “wants” to gain an electron. Atomization refers to the process of breaking down a molecule into its constituent atoms, while electronegativity is a measure of how strongly an atom attracts electrons in a chemical bond. Ionization refers to the process of removing an electron from an atom or molecule.