Question 1

Which of the following best explains why water is an effective solvent for ionic compounds such as NaCl?

Accepted Answer

Water molecules have a bent shape and are polar, allowing them to surround and stabilize ions.

Question 2

A solution of 0.50 mol of potassium sulfate ($$K_2SO_4) is $$dissolved in water. How many moles of ions are present in the solution?

Accepted Answer

$$1.0$$ mol $$K^+$$ and $$0.5$$ mol $$SO_4$$^{2-}$$

Question 3

Which of the following is the correct net ionic equation for the reaction between aqueous solutions of silver nitrate and sodium chromate?

Accepted Answer

$$2Ag^+(aq) + $$CrO_4$$^{2-}(aq) \rightarrow Ag_2CrO_4(s)$$

Question 4

Which of the following statements about strong acids and bases is correct?

Accepted Answer

Strong bases contain $$OH^- or$$ $$O^{2-}$$ ions and completely dissociate in water.

Question 5

A student mixes solutions of $$Na_2SO_4$$ and $$Sr(NO_3$)_2. $$What is the net ionic equation for the reaction that occurs?

Accepted Answer

$$SO_4$$^{2-}(aq) + $$Sr^{2+}(aq$$) \rightarrow $$SrSO_4(s$$)$$

Question 6

Which of the following best describes the role of water in an acid-base titration?

Accepted Answer

Water is the solvent that allows ions to move and react, and is also formed as a product in neutralization.

Question 7

Which of the following is the correct oxidation number for sulfur in $$H_2SO_4$$?

Accepted Answer

$$+6$$

Question 8

In the reaction $$2Al(s) + 3H_2SO_4(aq) \rightarrow Al_2$(SO_4$)_3(aq) + 3H_2(g)$$, which species is the oxidizing agent?

Accepted Answer

$$H_2SO_4(aq)$$

Question 9

Which of the following best explains why $$HI is a $$stronger acid than $$HF$$?

Accepted Answer

The H–I bond is weaker and the larger size of iodine makes it easier to lose a proton.

Question 10

Which of the following is the correct balanced molecular equation for the reaction between barium hydroxide and sulfuric acid?

Accepted Answer

$$Ba(OH)_2(aq) + H_2SO_4(aq) \rightarrow 2H_2O(l) + $$BaSO_4$$(aq)$$

Question 11

A sample of $$78.5 g of $$cesium bromide ($$CsBr) is $$dissolved in water. How many moles of $$Br^-$$ ions are present? (Molar mass of $$CsBr = 212.8 g/$$mol)

Accepted Answer

$$0.369$$ mol

Question 12

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 13

Which of the following is the correct total ionic equation for the reaction between $$2AgNO_3(aq)$$ and $$Na_2CrO_4(aq)$$?

Accepted Answer

$$2Ag^+(aq) + 2NO_3^-(aq) + 2Na^+(aq) + $$CrO_4$$^{2-}(aq) \rightarrow Ag_2CrO_4(s) + 2Na^+(aq) + 2NO_3^-(aq)$$

Question 14

Which of the following is a correct statement about oxidation and reduction?

Accepted Answer

Oxidation is the loss of electrons and reduction is the gain of electrons.

Question 15

In a redox titration, $$2.05 mL of$$ $$4.88 	imes 10$$^{-4}$$ M $$KMnO_4$$ is required to react with all the Ca$$^{2+}$$ in 1.00$ mL of blood. What is the amount of Ca$$^{2+}$$ (in mol) in 100$ mL of blood?

Accepted Answer

$$2.50 	imes 10$$^{-4}$$ mol

Question 16

Which of the following best describes the difference between a molecular equation, a total ionic equation, and a net ionic equation?

Accepted Answer

A molecular equation shows all substances as molecules, a total ionic equation shows all ions, and a net ionic equation shows only the ions that participate in the reaction.

Question 17

Which of the following is the correct net ionic equation for the reaction between hydrochloric acid and sodium hydroxide?

Accepted Answer

$$H^+(aq) + OH^-(aq) \rightarrow H_2O(l)$$

Question 18

Which of the following best explains why $$HF is a $$weak acid while $$HCl is a $$strong acid?

Accepted Answer

$$HF$$ has a stronger H–F bond, making it harder to lose a proton.

Chapter 4: The Major Classes of Chemical Reactions

Guida di studio - Domande di pratica

Study guide - Flashcard