BS Chemistry Fundamentals 2 — Questions and Answers
Question 1: What is an ionic bond?
- A bond formed by the electrostatic attraction between oppositely charged ions (Correct answer)
- A bond formed by equal sharing of electrons between atoms
- A weak intermolecular force between polar molecules
- A bond formed by overlapping atomic orbitals
Correct answer: A bond formed by the electrostatic attraction between oppositely charged ions
Ionic bonds result from the transfer of electrons from one atom to another, creating positively and negatively charged ions that attract each other.
Question 2: What is an acid according to the Bronsted-Lowry definition?
- A substance that donates a proton (H+) to another substance (Correct answer)
- A substance that accepts a proton from another substance
- A substance that produces OH- ions in water
- A substance with a pH greater than 7
Correct answer: A substance that donates a proton (H+) to another substance
The Bronsted-Lowry definition identifies acids as proton donors — they give up hydrogen ions (H+) in a reaction.
Question 3: What is the mole in chemistry?
- A unit representing 6.022 × 10²³ particles of a substance (Correct answer)
- The mass in grams of one molecule of a compound
- The volume occupied by one gram of gas at STP
- A unit of concentration equal to one gram per liter
Correct answer: A unit representing 6.022 × 10²³ particles of a substance
A mole is Avogadro's number (6.022 × 10²³) of particles, allowing chemists to relate atomic-scale quantities to measurable amounts.
Question 4: What is oxidation in a chemical reaction?
- The loss of electrons by an atom or molecule (Correct answer)
- The gain of electrons by an atom or molecule
- The addition of oxygen to a compound
- The removal of hydrogen from an organic molecule
Correct answer: The loss of electrons by an atom or molecule
Oxidation is defined as the loss of electrons; it always occurs alongside reduction (gain of electrons) in redox reactions.
Question 5: What is a catalyst?
- A substance that increases the rate of a reaction without being consumed (Correct answer)
- A substance that slows down a chemical reaction
- A product formed during the initial stage of a reaction
- An inhibitor that blocks enzyme activity
Correct answer: A substance that increases the rate of a reaction without being consumed
A catalyst lowers the activation energy required for a reaction to proceed, speeding it up without being permanently changed or consumed.
Question 6: What does the periodic table organize elements by?
- Increasing atomic number and recurring chemical properties (Correct answer)
- Alphabetical order of element names
- Decreasing atomic mass
- Order of discovery by scientists
Correct answer: Increasing atomic number and recurring chemical properties
The periodic table arranges elements by increasing atomic number, with elements having similar chemical properties grouped in the same vertical column (group).
BS Chemistry Fundamentals 2
What is an ionic bond?