Q: A student records the mass of an empty beaker as 45.67 g and the mass of the beaker plus a sample as 67.89 g. What is the mass of the sample?

$$67.89 \text{ g} - 45.67 \text{ g} = 22.22 \text{ g}$$

Q: A student is asked to calculate the density of a metal sample. The mass is 15.0 g and the volume is 3.0 mL. What is the density?

$$\frac{15.0 \text{ g}}{3.0 \text{ mL}} = 5.0 \text{ g/mL}$$

Question 1

Which of the following best describes the scientific method as it applies to chemistry?

Accepted Answer

A systematic approach involving observation, hypothesis formation, experimentation, and analysis to understand chemical phenomena.

Question 2

A student mixes two clear solutions in a beaker and observes the formation of a solid precipitate. Which type of chemical change has occurred?

Accepted Answer

Chemical change, because a new substance (precipitate) has formed.

Question 3

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

Accepted Answer

Reactivity with oxygen

Question 4

A laboratory experiment requires you to measure 25.00 mL of a solution. Which piece of equipment would provide the most accurate measurement?

Accepted Answer

Buret

Question 5

Which of the following best explains why it is important to wear safety goggles in the chemistry laboratory?

Accepted Answer

To protect your eyes from chemical splashes and flying debris.

Question 6

Which of the following equations correctly represents the law of conservation of mass for the reaction: $$2H_2 + O_2$ \rightarrow 2H_2O$$?

Accepted Answer

The total mass of reactants equals the total mass of products.

Question 7

A student is asked to identify an unknown white powder. Which of the following steps should be performed first according to the scientific method?

Accepted Answer

Observe and record the physical properties of the powder.

Question 8

Which of the following statements about elements and compounds is correct?

Accepted Answer

Compounds are made up of two or more elements chemically combined in fixed proportions.

Question 9

A student records the mass of an empty beaker as 45.67 g and the mass of the beaker plus a sample as 67.89 g. What is the mass of the sample?

Accepted Answer

$$67.89 	ext{ g} - 45.67 	ext{ g} = 22.22 	ext{ g}$$

Question 10

Which of the following best describes a mixture?

Accepted Answer

A combination of two or more substances that retain their individual properties.

Question 11

A student is heating a solution in a test tube and notices bubbles forming. What is the most likely explanation for this observation?

Accepted Answer

The solution is boiling and a physical change is taking place.

Question 12

Which of the following is the best example of a physical change?

Accepted Answer

Dissolving sugar in water.

Question 13

Which of the following is a correct safety procedure when handling acids in the laboratory?

Accepted Answer

Always add acid to water.

Question 14

A student is asked to calculate the density of a metal sample. The mass is 15.0 g and the volume is 3.0 mL. What is the density?

Accepted Answer

$$\frac{15.0 	ext{ g}}{3.0 	ext{ mL}} = 5.0 	ext{ g/mL}$$

Question 15

Which of the following best describes the difference between a hypothesis and a theory in chemistry?

Accepted Answer

A hypothesis is a tentative explanation that can be tested, while a theory is a well-supported explanation based on evidence.

Question 16

A student is given a sample of an unknown liquid and asked to determine if it is water. Which property would be most useful for identification?

Accepted Answer

Boiling point

Question 17

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

Accepted Answer

Sand and iron filings

Question 18

A student is asked to balance the following chemical equation: $$\_\_\_\_ H_2$ + \_\_\_\_ O_2$ \rightarrow \_\_\_\_ H_2O. $$What are the correct coefficients?

Accepted Answer

2, 1, 2

Question 19

Which of the following best describes the role of laboratory experiments in chemistry education?

Accepted Answer

To provide hands-on experience with chemical concepts and reinforce theoretical knowledge.

Question 20

A student is asked to analyze a scenario where a metal reacts with acid to produce hydrogen gas. Which of the following best represents the type of reaction?

Accepted Answer

Single displacement reaction

CHM 101 - Fundamentals of Chemistry: Syllabus and Course Overview Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard