Q: A food contains 10 g of fat, 5 g of protein, and 20 g of carbohydrates. Using the energy values (fat: 9 kcal/g, protein: 4 kcal/g, carbohydrate: 4 kcal/g), what is the total energy content of the food?

$$(10 \times 9) + (5 \times 4) + (20 \times 4) = 90 + 20 + 80 = 190$$ kcal

Q: A sample of water is heated from $$20^\circC to$$ $$80^\circC. If $$the mass of water is 100 g and the specific heat is $$4.18 \frac{J}{g \cdot ^\circ C}$$, how much energy is required?

$$q = m \times c \times \Delta T = 100 \times 4.18 \times (80 - 20) = 100 \times 4.18 \times 60 = 25,080 J$$

Q: Which of the following is the correct formula for density?

$$\text{Density} = \frac{\text{mass}}{\text{volume}}$$

Q: Which of the following is a correct conversion factor for changing milliliters to liters?

$$1 \text{ mL} = 0.001 \text{ L}$$

Q: Which of the following is the correct formula for calculating energy using mass and change in temperature?

$$q = m \times c \times \Delta T$$

Question 1

Which of the following statements best describes a scientific method in chemistry?

Accepted Answer

It is a process involving hypothesis, observation, experiment, and conclusion.

Question 2

A student measures the mass of a sample three times and gets values of 2.1 g, 2.2 g, and 2.0 g. The accepted value is 2.5 g. Which statement best describes the student's measurements?

Accepted Answer

The measurements are precise but not accurate.

Question 3

Which of the following is a physical change?

Accepted Answer

Melting ice into water.

Question 4

A patient receives 250 mL of a solution. Convert this volume to liters.

Accepted Answer

$$0.250 L$$

Question 5

Which of the following is a mixture?

Accepted Answer

Air

Question 6

A food contains 10 g of fat, 5 g of protein, and 20 g of carbohydrates. Using the energy values (fat: 9 kcal/g, protein: 4 kcal/g, carbohydrate: 4 kcal/g), what is the total energy content of the food?

Accepted Answer

$$(10 	imes 9) + (5 	imes 4) + (20 	imes 4) = 90 + 20 + 80 = 190$$ kcal

Question 7

Which of the following best describes an element?

Accepted Answer

A pure substance that cannot be broken down by chemical means.

Question 8

Which of the following is the correct symbol for potassium?

Accepted Answer

K

Question 9

A sample of water is heated from $$20^\circC to$$ $$80^\circC. If $$the mass of water is 100 g and the specific heat is $$4.18 \frac{J}{g \cdot ^\circ C}$$, how much energy is required?

Accepted Answer

$$q = m 	imes c 	imes \Delta T = 100 	imes 4.18 	imes (80 - 20) = 100 	imes 4.18 	imes 60 = 25,080 J$$

Question 10

Which of the following is NOT a chemical property?

Accepted Answer

Color

Question 11

Which of the following is the correct formula for density?

Accepted Answer

$$	ext{Density} = \frac{	ext{mass}}{	ext{volume}}$$

Question 12

Which of the following is a correct conversion factor for changing milliliters to liters?

Accepted Answer

$$1 	ext{ mL} = 0.001 	ext{ L}$$

Question 13

Which of the following is a correct statement about isotopes?

Accepted Answer

Isotopes have the same number of protons but different numbers of neutrons.

Question 14

Which of the following is the correct electron configuration for a neutral atom of oxygen (atomic number 8)?

Accepted Answer

$$1s^2$$ $$2s^2$$ $$2p^4$$

Question 15

Which of the following best describes a beta particle?

Accepted Answer

An electron emitted from the nucleus

Question 16

A radioactive isotope has a half-life of 10 years. If you start with 80 g, how much will remain after 30 years?

Accepted Answer

10 g

Question 17

Which of the following is the correct symbol for an alpha particle?

Accepted Answer

$$^4_2He$$

Question 18

Which of the following elements is a noble gas?

Accepted Answer

Neon (Ne)

Question 19

Which of the following is the correct formula for calculating energy using mass and change in temperature?

Accepted Answer

$$q = m 	imes c 	imes \Delta T$$

Question 20

Which of the following is a correct statement about the periodic table?

Accepted Answer

Groups are vertical columns and periods are horizontal rows.

GOB Chemistry Study Notes: Chapters 1–5 (Chemistry in Our Lives, Measurements, Matter & Energy, Atoms & Elements, Nuclear Chemistry)

Guida di studio - Domande di pratica

Study guide - Flashcard