Chem 280 Midterm – General Chemistry (Allied Health /
Nursing) Complete 200-Practice-Question Bank with Verified
Answers & Explanations
BLOCK 1: MATTER, MEASUREMENT, AND UNITS (Questions 1–30)
Q1. Chemistry is the study of:
A) Living organisms only
B) Matter and its transformations
C) Mathematical principles
D) The Earth’s geological composition
Answer: B
Explanation: Chemistry studies the composition, structure, properties, and changes of matter – the
material that makes up the universe.
Q2. Which of the following is an example of a qualitative observation?
A) The water temperature is 25°C.
B) The solution turned blue.
C) The mass is 10.5 g.
D) The volume is 50.0 mL.
Answer: B
Explanation: Qualitative observations describe properties without numbers (color, odor, state).
Quantitative observations involve measurements with numbers and units.
Q3. The SI base unit of length is the:
A) Centimeter
B) Meter
,C) Kilometer
D) Inch
Answer: B
Explanation: The meter (m) is the SI base unit of length. Other units are derived or metric but not base
SI.
Q4. The SI base unit of mass is the:
A) Gram
B) Pound
C) Kilogram
D) Ounce
Answer: C
Explanation: The kilogram (kg) is the SI base unit of mass. The gram is a derived unit (1 kg = 1000 g).
Q5. The SI base unit of time is the:
A) Minute
B) Hour
C) Second
D) Day
Answer: C
Explanation: The second (s) is the SI base unit of time.
Q6. Which prefix represents \(10^{-3}\)?
A) Milli
B) Centi
C) Micro
,D) Kilo
Answer: A
Explanation: milli‑ = \(10^{-3}\) (0.001). Centi = \(10^{-2}\), micro = \(10^{-6}\), kilo = \(10^{3}\).
Q7. How many significant figures are in 0.003040?
A) 7
B) 5
C) 4
D) 3
Answer: C
Explanation: Leading zeros are not significant. The digits “3040” – the zero after 4 is significant because
it’s after a non‑zero digit and decimal is present. So 4 significant figures.
Q8. Convert 1.25 L to mL.
A) 0.00125 mL
B) 125 mL
C) 1250 mL
D) 12.5 mL
Answer: C
Explanation: 1 L = 1000 mL; 1.25 × 1000 = 1250 mL.
Q9. Convert 25°C to Kelvin.
A) 298 K
B) 248 K
C) 273 K
D) 300 K
, Answer: A
Explanation: K = °C + 273.15 ≈ 25 + 273 = 298 K.
Q10. A graduated cylinder contains 50.0 mL of water. A rock added raises the level to 65.2 mL. The
rock’s volume is:
A) 15.2 mL
B) 50.0 mL
C) 65.2 mL
D) 115.2 mL
Answer: A
Explanation: Volume of rock = final volume – initial volume = 65.2 – 50.0 = 15.2 mL.
Q11. Density is defined as:
A) Mass × Volume
B) Volume / Mass
C) Mass / Volume
D) Mass + Volume
Answer: C
Explanation: Density = mass / volume (g/mL or g/cm³).
Q12. What is the density of a substance with mass 25.0 g and volume 5.0 mL?
A) 0.20 g/mL
B) 5.0 g/mL
C) 125 g/mL
D) 2.0 g/mL
Nursing) Complete 200-Practice-Question Bank with Verified
Answers & Explanations
BLOCK 1: MATTER, MEASUREMENT, AND UNITS (Questions 1–30)
Q1. Chemistry is the study of:
A) Living organisms only
B) Matter and its transformations
C) Mathematical principles
D) The Earth’s geological composition
Answer: B
Explanation: Chemistry studies the composition, structure, properties, and changes of matter – the
material that makes up the universe.
Q2. Which of the following is an example of a qualitative observation?
A) The water temperature is 25°C.
B) The solution turned blue.
C) The mass is 10.5 g.
D) The volume is 50.0 mL.
Answer: B
Explanation: Qualitative observations describe properties without numbers (color, odor, state).
Quantitative observations involve measurements with numbers and units.
Q3. The SI base unit of length is the:
A) Centimeter
B) Meter
,C) Kilometer
D) Inch
Answer: B
Explanation: The meter (m) is the SI base unit of length. Other units are derived or metric but not base
SI.
Q4. The SI base unit of mass is the:
A) Gram
B) Pound
C) Kilogram
D) Ounce
Answer: C
Explanation: The kilogram (kg) is the SI base unit of mass. The gram is a derived unit (1 kg = 1000 g).
Q5. The SI base unit of time is the:
A) Minute
B) Hour
C) Second
D) Day
Answer: C
Explanation: The second (s) is the SI base unit of time.
Q6. Which prefix represents \(10^{-3}\)?
A) Milli
B) Centi
C) Micro
,D) Kilo
Answer: A
Explanation: milli‑ = \(10^{-3}\) (0.001). Centi = \(10^{-2}\), micro = \(10^{-6}\), kilo = \(10^{3}\).
Q7. How many significant figures are in 0.003040?
A) 7
B) 5
C) 4
D) 3
Answer: C
Explanation: Leading zeros are not significant. The digits “3040” – the zero after 4 is significant because
it’s after a non‑zero digit and decimal is present. So 4 significant figures.
Q8. Convert 1.25 L to mL.
A) 0.00125 mL
B) 125 mL
C) 1250 mL
D) 12.5 mL
Answer: C
Explanation: 1 L = 1000 mL; 1.25 × 1000 = 1250 mL.
Q9. Convert 25°C to Kelvin.
A) 298 K
B) 248 K
C) 273 K
D) 300 K
, Answer: A
Explanation: K = °C + 273.15 ≈ 25 + 273 = 298 K.
Q10. A graduated cylinder contains 50.0 mL of water. A rock added raises the level to 65.2 mL. The
rock’s volume is:
A) 15.2 mL
B) 50.0 mL
C) 65.2 mL
D) 115.2 mL
Answer: A
Explanation: Volume of rock = final volume – initial volume = 65.2 – 50.0 = 15.2 mL.
Q11. Density is defined as:
A) Mass × Volume
B) Volume / Mass
C) Mass / Volume
D) Mass + Volume
Answer: C
Explanation: Density = mass / volume (g/mL or g/cm³).
Q12. What is the density of a substance with mass 25.0 g and volume 5.0 mL?
A) 0.20 g/mL
B) 5.0 g/mL
C) 125 g/mL
D) 2.0 g/mL
