NYSTCE ATAS NYSTCE Chemistry 3 — Questions and Answers
Question 1: According to Boyle's Law, if the pressure on a gas doubles at constant temperature, what happens to the volume?
- It doubles
- It stays the same
- It is reduced by half (Correct answer)
- It quadruples
Correct answer: It is reduced by half
Boyle's Law states that pressure and volume are inversely proportional at constant temperature, so doubling pressure halves the volume.
Question 2: Which of the following is a physical change?
- Iron rusting
- Wood burning
- Water boiling (Correct answer)
- Baking bread
Correct answer: Water boiling
Boiling water is a physical change because only the state changes from liquid to gas; the chemical composition of water (H₂O) remains the same.
Question 3: The pH scale measures the concentration of which ion in a solution?
- Hydroxide ions (OH⁻)
- Hydronium ions (H₃O⁺) or hydrogen ions (H⁺) (Correct answer)
- Sodium ions (Na⁺)
- Chloride ions (Cl⁻)
Correct answer: Hydronium ions (H₃O⁺) or hydrogen ions (H⁺)
pH measures the concentration of hydrogen ions (H⁺) or hydronium ions (H₃O⁺) in solution; lower pH means higher H⁺ concentration.
Question 4: Carbon-14 is used in radioactive dating because it undergoes radioactive decay. This is an example of which type of nuclear change?
- Nuclear fission
- Nuclear fusion
- Transmutation by alpha decay
- Transmutation by beta decay (Correct answer)
Correct answer: Transmutation by beta decay
Carbon-14 decays by beta emission, converting a neutron to a proton, which is a form of transmutation called beta decay.
Question 5: Which laboratory tool is MOST appropriate for measuring the volume of a liquid accurately?
- Beaker
- Erlenmeyer flask
- Graduated cylinder (Correct answer)
- Test tube
Correct answer: Graduated cylinder
A graduated cylinder has precise volume markings and is specifically designed for accurate liquid volume measurement in lab settings.
Question 6: In the formula H₂SO₄, how many atoms of oxygen are present?
- 2
- 3
- 4 (Correct answer)
- 6
Correct answer: 4
The subscript 4 after O in H₂SO₄ indicates there are 4 oxygen atoms in each formula unit of sulfuric acid.
Question 7: A solution with a pH of 9 is best described as:
- Strongly acidic
- Weakly acidic
- Neutral
- Basic (alkaline) (Correct answer)
Correct answer: Basic (alkaline)
pH values above 7 indicate a basic (alkaline) solution; pH 7 is neutral and values below 7 are acidic.
NYSTCE ATAS NYSTCE Chemistry 3
According to Boyle's Law, if the pressure on a gas doubles at constant temperature, what happens to the volume?