Q: A student measures the mass of a metal sample as 45.6 g and its volume as 12.0 mL. What is the density of the metal, and how many significant figures should the answer have?

Density: $$3.80\ \text{g/mL}$$, 3 significant figures

Q: Which of the following is a pure substance?

Carbon dioxide ($$\text{CO}_2)$$

Q: Which of the following is an example of a covalent bond?

The bond between two hydrogen atoms in $$\text{H}_2$$

Q: A sample of liquid has a mass of 25.0 g and a volume of 20.0 mL. What is its density, and what does this value indicate about the liquid compared to water?

Density: $$1.25\ \text{g/mL}$$; the liquid is denser than water.

Question 1

Which of the following statements best describes a compound?

Accepted Answer

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

Question 2

A student measures the mass of a metal sample as 45.6 g and its volume as 12.0 mL. What is the density of the metal, and how many significant figures should the answer have?

Accepted Answer

Density: $$3.80\ 	ext{g/mL}$$, 3 significant figures

Question 3

Which of the following is NOT an SI base unit?

Accepted Answer

Liter

Question 4

Which type of bond is formed when sodium reacts with chlorine to produce sodium chloride?

Accepted Answer

Ionic bond

Question 5

Which of the following best describes the location of protons, neutrons, and electrons in an atom?

Accepted Answer

Protons and neutrons are in the nucleus; electrons orbit the nucleus.

Question 6

A chemist needs to measure the amount of a substance for a reaction. Which SI unit should they use?

Accepted Answer

Mole

Question 7

Which of the following is a pure substance?

Accepted Answer

Carbon dioxide ($$	ext{CO}_2)$$

Question 8

A student records the following measurements: 0.00450 m, 2.30 g, and 100.0 mL. How many significant figures are in each measurement, respectively?

Accepted Answer

3, 3, 4

Question 9

Which of the following best explains why water ($$	ext{H}_2	ext{O}) is $$considered a compound?

Accepted Answer

It consists of two elements chemically combined in a fixed ratio.

Question 10

Which of the following scenarios demonstrates the application of density in a real-world context?

Accepted Answer

A ship floats because its average density is less than that of water.

Question 11

Which of the following is the correct formula for calculating density?

Accepted Answer

$$d = \frac{m}{V}$$

Question 12

Which property distinguishes a compound from a mixture?

Accepted Answer

A compound has a fixed composition and can only be separated by chemical means.

Question 13

Which of the following is an example of a covalent bond?

Accepted Answer

The bond between two hydrogen atoms in $$	ext{H}_2$$

Question 14

Which statement about the periodic table is correct?

Accepted Answer

Elements are organized by increasing atomic number.

Question 15

A sample of liquid has a mass of 25.0 g and a volume of 20.0 mL. What is its density, and what does this value indicate about the liquid compared to water?

Accepted Answer

Density: $$1.25\ 	ext{g/mL}$$; the liquid is denser than water.

Question 16

Which of the following is NOT a characteristic of a pure substance?

Accepted Answer

Variable composition

Question 17

Which scenario best illustrates the concept of significant figures in measurement?

Accepted Answer

Reporting a mass as 12.30 g when measured with a balance that reads to the nearest 0.01 g.

Question 18

Which of the following best describes the difference between an element and a compound?

Accepted Answer

An element cannot be broken down by chemical means, while a compound can.

Question 19

Which of the following is the correct SI unit for temperature?

Accepted Answer

Kelvin

Question 20

A patient receives a dose of medication based on their body mass. If the medication requires 0.05 g per kg and the patient weighs 70 kg, how much medication should be administered?

Accepted Answer

$$3.5\ 	ext{g}$$

Matter, Measurement, and Atomic Structure: General Chemistry Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard