Question 1

Which of the following best describes a chemical property?

Accepted Answer

Sodium reacts violently with water.

Question 2

A sample of water is heated from $$25^\circ \mathrm{C} to$$ $$100^\circ \mathrm{C}. $$Which of the following best describes the change that occurs when the water boils?

Accepted Answer

A physical change, because the water changes state but not composition.

Question 3

Which of the following is a homogeneous mixture?

Accepted Answer

Sweetened tea

Question 4

A student measures the mass of a coin as $$5.23 g $$and its volume as $$0.60 mL. $$What is the density of the coin, and how many significant figures should the answer have?

Accepted Answer

$$8.72\ \mathrm{g/mL}$$, 3 significant figures

Question 5

Which of the following statements about the scientific method is correct?

Accepted Answer

A law summarizes past observations and predicts future ones.

Question 6

Convert $$25^\circ \mathrm{C} to $$Kelvin.

Accepted Answer

$$298.15\ \mathrm{K}$$

Question 7

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

Accepted Answer

Dissolving sugar in water

Question 8

A patient’s body temperature is measured as $$102.2^\circ \mathrm{F}. $$What is this temperature in Celsius? (Use $$^\circ \mathrm{C} = ( ^\circ \mathrm{F} - 32 ) 	imes \frac{5}{9})$$

Accepted Answer

$$39.0^\circ \mathrm{C}$$

Question 9

Which of the following best describes an element?

Accepted Answer

A substance that cannot be broken down into simpler substances by chemical means.

Question 10

A block of metal has a mass of $$250 g $$and a volume of $$50.0 mL. If $$the block is dropped into a graduated cylinder containing $$100.0 mL of $$water, what will be the final volume reading?

Accepted Answer

$$150.0 mL$$

Question 11

Which of the following is a correct statement about energy in chemical changes?

Accepted Answer

Energy is conserved; it can be converted from one form to another.

Question 12

Which of the following is a heterogeneous mixture?

Accepted Answer

Oil and water

Question 13

A student records the following measurements: $$2.50 m$$, $$0.0030 m$$, and $$4.0 m. $$How many significant figures are in the sum of these measurements?

Accepted Answer

2

Question 14

Which of the following is NOT a correct SI base unit?

Accepted Answer

Liter for volume

Question 15

A sample of ethanol has a density of $$0.789\ \mathrm{g/mL}. $$What is the mass of $$250.0 mL of $$ethanol?

Accepted Answer

$$197.3 g$$

Question 16

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

Accepted Answer

A silver spoon tarnishing

Question 17

Which of the following statements about atoms and molecules is correct?

Accepted Answer

Molecules are groups of two or more atoms bonded together.

Question 18

A solution is prepared by dissolving $$10.0 g of $$NaCl in $$90.0 g of $$water. Which term best describes this mixture?

Accepted Answer

Homogeneous mixture

Question 19

Which of the following is a correct conversion factor for converting milligrams to grams?

Accepted Answer

$$1\ \mathrm{g} = 1000\ \mathrm{mg}$$

Question 20

A chemist needs to prepare $$500.0 mL of a $$solution. If the density of the solution is $$1.10\ \mathrm{g/mL}$$, what is the total mass of the solution?

Accepted Answer

$$550 g$$

General Chemistry I: Matter, Measurement, and Problem Solving

Guida di studio - Domande di pratica

Study guide - Flashcard