Q: A sample of metal has a mass of 25.0 g and a volume of 5.00 cm$$^3. $$What is its density?

$$d = \frac{25.0\ \text{g}}{5.00\ \text{cm}^3} = 5.00\ \text{g/cm}^3$$

Q: Convert 0.250 kilojoules (kJ) to joules (J).

$$0.250\ \text{kJ} \times 1000 = 250\ \text{J}$$

Q: A 100.0 g sample of water is heated from 25.0°C to 75.0°C. If the specific heat capacity of water is $$4.18\ \text{J/g}^\circ\text{C}$$, how much heat ($$q) is $$absorbed?

$$q = 100.0 \times 4.18 \times (75.0 - 25.0) = 20,900\ \text{J}$$

Q: A temperature is recorded as 68°F. What is this temperature in Kelvin (K)?

$$K = \frac{68 - 32}{1.8} + 273.15 = 293.15\ \text{K}$$

Q: Which of the following is a correct conversion factor for converting inches to centimeters?

$$1\ \text{in} = 2.54\ \text{cm}$$

Question 1

Which of the following best describes a scientific law?

Accepted Answer

A brief statement that summarizes past observations and predicts future ones.

Question 2

A student measures the mass of a sample as 0.00450 g. How many significant figures does this measurement have?

Accepted Answer

3

Question 3

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

Accepted Answer

Iron reacts with oxygen to form rust.

Question 4

A sample of metal has a mass of 25.0 g and a volume of 5.00 cm$$^3. $$What is its density?

Accepted Answer

$$d = \frac{25.0\ 	ext{g}}{5.00\ 	ext{cm}^3} = 5.00\ 	ext{g/cm}^3$$

Question 5

Which of the following best describes a homogeneous mixture?

Accepted Answer

A mixture in which the composition is uniform throughout.

Question 6

Convert 0.250 kilojoules (kJ) to joules (J).

Accepted Answer

$$0.250\ 	ext{kJ} 	imes 1000 = 250\ 	ext{J}$$

Question 7

Which of the following is a physical change?

Accepted Answer

Dissolving sugar in water.

Question 8

A 100.0 g sample of water is heated from 25.0°C to 75.0°C. If the specific heat capacity of water is $$4.18\ 	ext{J/g}^\circ	ext{C}$$, how much heat ($$q) is $$absorbed?

Accepted Answer

$$q = 100.0 	imes 4.18 	imes (75.0 - 25.0) = 20,900\ 	ext{J}$$

Question 9

Which of the following statements about energy is correct?

Accepted Answer

Energy is the capacity to do work.

Question 10

A temperature is recorded as 68°F. What is this temperature in Kelvin (K)?

Accepted Answer

$$K = \frac{68 - 32}{1.8} + 273.15 = 293.15\ 	ext{K}$$

Question 11

Which of the following is NOT a step in the scientific method?

Accepted Answer

Ignoring experimental results

Question 12

Which of the following is a correct conversion factor for converting inches to centimeters?

Accepted Answer

$$1\ 	ext{in} = 2.54\ 	ext{cm}$$

Question 13

Which of the following best describes a compound?

Accepted Answer

A substance composed of two or more elements chemically combined in a fixed ratio.

Question 14

A sample of gasoline has a density of $$0.70\ 	ext{g/mL}. $$What is the mass of 2.0 L of gasoline? (1 L = 1000 mL)

Accepted Answer

$$0.70 	imes 2000 = 1400\ 	ext{g}$$

Question 15

Which of the following is an example of potential energy?

Accepted Answer

A stretched rubber band

Question 16

Which of the following is a correct statement of the law of conservation of mass?

Accepted Answer

In a chemical reaction, matter is neither created nor destroyed.

Question 17

A 50.0 g sample of a substance absorbs 500 J of heat, causing its temperature to increase by 10.0°C. What is the specific heat capacity ($$C) of $$the substance?

Accepted Answer

$$C = \frac{500}{50.0 	imes 10.0} = 1.0\ 	ext{J/g}^\circ	ext{C}$$

Question 18

Which of the following is a correct statement about the difference between physical and chemical changes?

Accepted Answer

A physical change results in a different form of the same substance, while a chemical change results in a completely new substance.

Question 19

Which of the following is the correct scientific notation for 0.00056?

Accepted Answer

$$5.6 	imes 10$$^{-4}$$

Exam 1

Guida di studio - Domande di pratica

Study guide - Flashcard