Q: A sample of water has a mass of 32.1 g and a density of 0.99823 g/mL at 20°C. What is the volume of water in mL?

$$\frac{32.1}{0.99823} = 32.2\ \text{mL}$$

Q: Convert 321 nm to meters using dimensional analysis.

$$321 \times 10$$^{-9}$$\ \text{m} = 3.21 \times 10$$^{-7}$$\ \text{m}$$

Q: A 5.0 g object is placed in a graduated cylinder containing water. The water level rises from 65.0 mL to 90.0 mL. What is the density of the object?

$$\frac{5.0}{25.0} = 0.20\ \text{g/mL}$$

Q: A student wants to convert 4.50 lbs of iron to grams. Which conversion factors should be used?

$$1\ \text{kg} = 2.2046\ \text{lbs}$$ and $$1\ \text{kg} = 1000\ \text{g}$$

Question 1

Which of the following best describes the change occurring when iron rusts, as shown in the image of the rusty tractor?

Accepted Answer

A chemical change, because the iron reacts with oxygen to form a new substance.

Question 2

In the diagram showing three states of matter (A, B, C), which state is represented by C, and what is a key property of this state?

Accepted Answer

Gas; atoms are far apart and move at high velocities.

Question 3

A student mixes oil and water in a glass, as shown in the image. What type of mixture is formed and why?

Accepted Answer

Heterogeneous mixture, because the substances remain separate and have non-uniform consistency.

Question 4

Which of the following is an example of an extensive property?

Accepted Answer

Mass

Question 5

A sample of water has a mass of 32.1 g and a density of 0.99823 g/mL at 20°C. What is the volume of water in mL?

Accepted Answer

$$\frac{32.1}{0.99823} = 32.2\ 	ext{mL}$$

Question 6

Which SI unit is used to measure temperature?

Accepted Answer

Kelvin (K)

Question 7

Convert 321 nm to meters using dimensional analysis.

Accepted Answer

$$321 	imes 10$$^{-9}$$\ 	ext{m} = 3.21 	imes 10$$^{-7}$$\ 	ext{m}$$

Question 8

Which of the following best describes the scientific method as shown in the diagram?

Accepted Answer

A cyclical process involving observation, hypothesis, experimentation, and theory development.

Question 9

A student measures the length of a pencil using two different rulers, one with more increments than the other. Which ruler will provide a more precise measurement and why?

Accepted Answer

The ruler with more increments, because it allows for greater reproducibility and precision.

Question 10

Which of the following is NOT a significant figure in the number 0.004320?

Accepted Answer

The zeroes before the 4

Question 11

Which equation correctly converts Celsius to Kelvin?

Accepted Answer

$$K = C + 273.15$$

Question 12

A 5.0 g object is placed in a graduated cylinder containing water. The water level rises from 65.0 mL to 90.0 mL. What is the density of the object?

Accepted Answer

$$\frac{5.0}{25.0} = 0.20\ 	ext{g/mL}$$

Question 13

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

Accepted Answer

Boiling point

Question 14

Which of the following statements about scientific notation is correct?

Accepted Answer

The exponent indicates how many places the decimal is moved.

Question 15

Which of the following is an example of a homogeneous mixture?

Accepted Answer

A glass of ocean water

Question 16

Which of the following is the correct value for Avogadro’s number?

Accepted Answer

$$6.022 	imes 10$$^{23}$$

Question 17

Which type of energy is associated with the motion of molecules and leads to a change in temperature?

Accepted Answer

Kinetic energy

Question 18

A student wants to convert 4.50 lbs of iron to grams. Which conversion factors should be used?

Accepted Answer

$$1\ 	ext{kg} = 2.2046\ 	ext{lbs}$$ and $$1\ 	ext{kg} = 1000\ 	ext{g}$$

Question 19

Which of the following is an intensive property?

Accepted Answer

Density

Chapter 1: Matter and Energy – Foundations of Chemistry

Guida di studio - Domande di pratica

Study guide - Flashcard