Q: Which of the following best explains why sodium chloride ($$\text{NaCl}) $$conducts electricity when dissolved in water but not as a solid?

In solid $$\text{NaCl}$$, ions are fixed in place and cannot move to conduct electricity.

Q: Which of the following is the correct balanced equation for the combustion of propane ($$\text{C}_3\text{H}_8) in $$oxygen?

$$\text{C}_3\text{H}_8 + 5\ \text{O}_2 \rightarrow 3\ \text{CO}_2 + 4\ \text{H}_2\text{O}$$

Q: Which of the following is a redox reaction?

$$2\ \text{Na} + 2\ \text{H}_2\text{O} \rightarrow 2\ \text{NaOH} + \text{H}_2$$

Q: Which of the following aqueous solutions will produce a precipitate when mixed?

$$\text{Pb(NO}_3)_2$$ and $$\text{KI}$$

Question 1

Which of the following statements best describes the difference between accuracy and precision in a laboratory measurement?

Accepted Answer

Accuracy refers to how close measurements are to the true value, while precision refers to how close measurements are to each other.

Question 2

A student measures the mass of a sample as 2.345 g. If the true mass is 2.365 g, what is the percent error of the measurement? Use the formula $$	ext{Percent Error} = \frac{|	ext{Experimental} - 	ext{True}|}{	ext{True}} 	imes 100\%.$$

Accepted Answer

$$0.85\%$$

Question 3

Which of the following is the correct electron configuration for a ground-state phosphorus atom ($$Z=15$$)?

Accepted Answer

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

Question 4

A sample of gas occupies $$4.00\ 	ext{L} at$$ $$1.00\ 	ext{atm}$$ and $$300\ 	ext{K}. If $$the pressure is increased to $$2.00\ 	ext{atm}$$ and the temperature is decreased to $$150\ 	ext{K}$$, what is the new volume? (Assume ideal gas behavior.)

Accepted Answer

$$1.00\ 	ext{L}$$

Question 5

Which of the following best explains why sodium chloride ($$	ext{NaCl}) $$conducts electricity when dissolved in water but not as a solid?

Accepted Answer

In solid $$	ext{NaCl}$$, ions are fixed in place and cannot move to conduct electricity.

Question 6

Which of the following is the correct balanced equation for the combustion of propane ($$	ext{C}_3	ext{H}_8) in $$oxygen?

Accepted Answer

$$	ext{C}_3	ext{H}_8 + 5\ 	ext{O}_2 ightarrow 3\ 	ext{CO}_2 + 4\ 	ext{H}_2	ext{O}$$

Question 7

Which quantum number determines the shape of an atomic orbital?

Accepted Answer

The azimuthal quantum number $$l$$

Question 8

A solution is prepared by dissolving $$0.50\ 	ext{mol} of$$ $$	ext{NaCl} in $$enough water to make $$1.0\ 	ext{L} of $$solution. What is the molarity of the solution?

Accepted Answer

$$0.50\ 	ext{M}$$

Question 9

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 10

Which of the following compounds is insoluble in water?

Accepted Answer

$$	ext{AgCl}$$

Question 11

A $$25.0\ 	ext{mL}$$ sample of $$0.200\ 	ext{M}\ 	ext{HCl} is $$titrated with $$0.100\ 	ext{M}\ 	ext{NaOH}. $$What volume of $$	ext{NaOH} is $$required to reach the equivalence point? (Assume the reaction is $$	ext{HCl} + 	ext{NaOH} ightarrow 	ext{NaCl} + 	ext{H}_2	ext{O})$$

Accepted Answer

$$50.0\ 	ext{mL}$$

Question 12

Which of the following best describes the emission of light from a hydrogen atom according to the Bohr model?

Accepted Answer

An electron falls from a higher energy level to a lower one, emitting a photon with energy $$E = h
u$$

Question 13

Which of the following is a redox reaction?

Accepted Answer

$$2\ 	ext{Na} + 2\ 	ext{H}_2	ext{O} ightarrow 2\ 	ext{NaOH} + 	ext{H}_2$$

Question 14

A $$10.0\ 	ext{g}$$ sample of calcium carbonate ($$	ext{CaCO}_3) is $$heated strongly. What mass of carbon dioxide ($$	ext{CO}_2) is $$produced? (Molar masses: $$	ext{CaCO}_3 = 100.1\ 	ext{g/mol}$$, $$	ext{CO}_2 = 44.0\ 	ext{g/mol}$$; reaction: $$	ext{CaCO}_3 ightarrow 	ext{CaO} + 	ext{CO}_2)$$

Accepted Answer

$$4.4\ 	ext{g}$$

Question 15

Which of the following statements about the periodic table is correct?

Accepted Answer

Elements in the same group have similar chemical properties because they have the same number of valence electrons.

Question 16

Which of the following aqueous solutions will produce a precipitate when mixed?

Accepted Answer

$$	ext{Pb(NO}_3)_2$$ and $$	ext{KI}$$

Question 17

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

Accepted Answer

Atomic radius decreases due to increasing effective nuclear charge.

Question 18

A sample contains $$3.01 	imes 10$$^{23}$$ molecules of $$	ext{CO}_2$$. What is the mass of the sample? (Molar mass of $$	ext{CO}_2 = 44.0\ 	ext{g/mol}$$)

Accepted Answer

$$22.0\ 	ext{g}$$

Question 19

Which of the following is the net ionic equation for the reaction between aqueous solutions of $$	ext{Ba(NO}_3)_2$$ and $$	ext{Na}_2	ext{SO}_4$$?

Accepted Answer

$$	ext{Ba}^{2+} (aq) + 	ext{SO}_4$$^{2-}$$ (aq) ightarrow 	ext{BaSO}_4 (s)$$

General Chemistry Practice Test Guidance (Chapters E–4)

Guida di studio - Domande di pratica

Study guide - Flashcard