$$\frac{15}{15+60} \times 100 = 20\%$$

Question 1

Which of the following best describes why sodium chloride (NaCl) conducts electricity when dissolved in water, but not as a solid?

Accepted Answer

Because the ions are free to move in solution, allowing electrical current to flow.

Question 2

Which of the following compounds is most likely to be insoluble in water?

Accepted Answer

CCl$$_4$$

Question 3

A solution is made by dissolving 15 grams of MgCl$$_2 in 60 $$grams of water. What is the percent by mass of MgCl$$_2 in $$the solution?

Accepted Answer

$$\frac{15}{15+60} 	imes 100 = 20\%$$

Question 4

Which of the following statements correctly compares ionic and covalent compounds?

Accepted Answer

Ionic compounds generally have higher melting points than covalent compounds.

Question 5

Which of the following best describes a saturated solution?

Accepted Answer

A solution in which no more solute can dissolve at a given temperature.

Question 6

Which of the following is a chemical property that distinguishes ionic compounds from covalent compounds?

Accepted Answer

Ionic compounds conduct electricity when dissolved in water.

Question 7

Which of the following best explains why sugar (C$$_{12}H$_{22}O$_{11}) $$does not conduct electricity when dissolved in water?

Accepted Answer

Sugar molecules do not break into ions in water.

Question 8

Which of the following best describes the type of bond in H$$_2O$$?

Accepted Answer

Covalent bond formed by sharing electrons.

Question 9

A student adds more salt to a saturated saltwater solution at constant temperature. What will happen?

Accepted Answer

The added salt will not dissolve and will remain as a solid.

Question 10

Which of the following best describes the process of dissolving NaCl in water?

Accepted Answer

Na$$^+$$ and Cl$$^-$$ ions are surrounded by water molecules and separated from each other.

Question 11

Which of the following is an example of a mixture?

Accepted Answer

Air

Question 12

Which of the following best describes a compound?

Accepted Answer

A substance made of two or more elements chemically bonded in a fixed ratio.

Question 13

Which of the following will increase the concentration of a salt solution?

Accepted Answer

Adding more salt to the solution.

Question 14

Which of the following is a correct statement about mixtures and compounds?

Accepted Answer

Mixtures can be separated by physical means, while compounds require chemical means.

Question 15

Which of the following best describes the bond in MgO?

Accepted Answer

Ionic bond formed by transfer of electrons.

Question 16

A solution contains 18 grams of solute in 27 grams of solution. What is the percent by mass of the solute?

Accepted Answer

$$\frac{18}{27} 	imes 100 = 66.7\%$$

Question 17

Which of the following is true about covalent bonds?

Accepted Answer

They involve the sharing of electrons between atoms.

Question 18

Which of the following best describes a supersaturated solution?

Accepted Answer

A solution that contains more dissolved solute than is normally possible at a given temperature.

Question 19

Which of the following is a property of covalent compounds?

Accepted Answer

They generally have low melting and boiling points.

Question 20

Which of the following best explains why KNO$$_3 is $$more soluble in water at higher temperatures?

Accepted Answer

Increasing temperature increases the kinetic energy of water molecules, allowing more KNO$$_3 to $$dissolve.

Ionic vs. Covalent Compounds and Solubility: Study Notes

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