Q: Which of the following is the correct formula for percent by mass?

$$\text{Percent by mass} = \frac{\text{mass of solute}}{\text{mass of solution}} \times 100$$

Question 1

Which of the following statements best describes a chemical property?

Accepted Answer

Iron reacts with oxygen to form rust.

Question 2

A student mixes sand and salt together. Which type of mixture is formed?

Accepted Answer

Heterogeneous mixture

Question 3

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

Accepted Answer

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

Question 4

A sample contains $$2.50 	imes 10$$^{23}$$ molecules of water. How many moles of water are present?

Accepted Answer

$$0.415$$ mol

Question 5

Which statement about isotopes is correct?

Accepted Answer

Isotopes have the same number of protons and electrons, but different numbers of neutrons.

Question 6

Which experiment provided evidence for the existence of the nucleus in the atom?

Accepted Answer

Rutherford's gold foil experiment

Question 7

A compound contains $$40.0\%$$ carbon, $$6.7\%$$ hydrogen, and $$53.3\%$$ oxygen by mass. What is its empirical formula?

Accepted Answer

$$CH_2O$$

Question 8

Which of the following is a strong electrolyte?

Accepted Answer

Sodium chloride ($$NaCl)$$

Question 9

What is the oxidation number of sulfur in $$SO_2$$?

Accepted Answer

$$+4$$

Question 10

Which of the following best describes a precipitation reaction?

Accepted Answer

A reaction in which an insoluble solid forms when two solutions are mixed.

Question 11

A solution is prepared by dissolving $$5.00 g of$$ $$NaCl in $$enough water to make $$250 mL of $$solution. What is the molarity of the solution? ($$M_{NaCl} = 58.44 g/$$mol)

Accepted Answer

$$0.342 M$$

Question 12

Which of the following is the correct net ionic equation for the reaction between $$AgNO_3(aq$$)$$ and $$NaCl(aq)$$?

Accepted Answer

$$Ag^+(aq) + Cl^-(aq) \rightarrow AgCl(s)$$

Question 13

Which of the following statements about acids and bases is correct according to the Arrhenius definition?

Accepted Answer

An acid produces $$H^+$$ ions in water.

Question 14

A $$25.0 mL $$sample of $$0.100 M$$ $$HCl is $$titrated with $$0.100 M$$ $$NaOH. $$What volume of $$NaOH is $$required to reach the equivalence point?

Accepted Answer

$$25.0 mL$$

Question 15

Which of the following is the correct formula for percent by mass?

Accepted Answer

$$	ext{Percent by mass} = \frac{	ext{mass of solute}}{	ext{mass of solution}} 	imes 100$$

Question 16

Which of the following is a molecular compound?

Accepted Answer

$$CO_2$$

Question 17

Which statement about significant figures is correct?

Accepted Answer

All nonzero digits are significant.

Question 18

A student needs to prepare $$500 mL of$$ $$0.250 M$$ $$KNO_3$$ solution. How many grams of $$KNO_3$$ are required? ($$M_{$$KNO_3$$} = 101.1 g/$$mol)

Accepted Answer

$$12.6 g$$

Question 19

Which of the following best describes the law of conservation of mass?

Accepted Answer

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

General Chemistry I: Core Concepts and Learning Objectives

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드