Question 1

Which of the following best describes a chemical compound?

Accepted Answer

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

Question 2

Which of the following is the correct balanced equation for the combustion of methane ($$CH_4) in $$oxygen?

Accepted Answer

$$CH_4 + 2O_2$$ \rightarrow $$CO_2 + 2H_2O$

Question 3

A student measures the mass of a sample as 12.345 g. How many significant figures are in this measurement?

Accepted Answer

5

Question 4

Which of the following statements about isotopes is correct?

Accepted Answer

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

Question 5

Which of the following best explains why water is a polar molecule?

Accepted Answer

Water has a bent molecular geometry and an uneven distribution of electron density.

Question 6

A sample of gas occupies 2.0 L at 1.0 atm and 300 K. What will be its volume at 2.0 atm and 300 K? (Assume ideal gas behavior.)

Accepted Answer

$$1.0\ \mathrm{L}$$

Question 7

Which of the following is the correct electron configuration for a neutral atom of sodium ($$Na$$)?

Accepted Answer

$$1s^2$$\ $$2s^2$$\ $$2p^6$$\ $$3s^1$$

Question 8

Which of the following best describes the trend in atomic radius across a period from left to right in the periodic table?

Accepted Answer

Atomic radius decreases due to increasing nuclear charge.

Question 9

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

Accepted Answer

The total mass of reactants equals the total mass of products in a chemical reaction.

Question 10

A solution is prepared by dissolving 5.00 g of $$NaCl in $$enough water to make 250.0 mL of solution. What is the molarity of the solution? ($$M_{NaCl} = 58.44\ \mathrm{g/mol})$$

Accepted Answer

$$0.342\ \mathrm{M}$$

Question 11

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

Accepted Answer

Boiling water to produce steam.

Question 12

Which of the following best describes the type of bonding in sodium chloride ($$NaCl$$)?

Accepted Answer

Ionic bonding due to transfer of electrons from sodium to chlorine.

Question 13

Which of the following is the correct name for $$Fe_2O_3$$?

Accepted Answer

Iron(III) oxide

Question 14

A reaction releases 150 kJ of heat to the surroundings. Which of the following statements is correct?

Accepted Answer

The reaction is exothermic.

Question 15

Which of the following is the correct formula for calculating the density ($$d) of a $$substance?

Accepted Answer

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

Question 16

Which of the following laboratory practices is essential for safety when heating chemicals?

Accepted Answer

Always point the open end of a test tube away from yourself and others.

Question 17

Which of the following best describes the kinetic molecular theory as it applies to gases?

Accepted Answer

Gas particles move randomly and rapidly, and the volume of the particles is negligible compared to the container.

Question 18

Which of the following is the correct formula for converting Celsius temperature to Kelvin?

Accepted Answer

$$K = ^\circ C + 273.15$$

Question 19

Which of the following is a correct example of dimensional analysis for converting 5.0 km to meters?

Accepted Answer

$$5.0\ \mathrm{km} 	imes \frac{1000\ \mathrm{m}}{1\ \mathrm{km}} = 5000\ \mathrm{m}$$

Question 20

Which of the following best describes a synthesis reaction?

Accepted Answer

Two or more substances combine to form a single product.

CHEM 1411 General Chemistry I Syllabus and Course Structure

Guida di studio - Domande di pratica

Study guide - Flashcard