Question 1

Which property of water makes it the 'universal solvent' for many biological molecules?

Accepted Answer

Its polar nature, allowing it to form hydrogen bonds with solutes

Question 2

When table salt (NaCl) dissolves in water, what happens at the molecular level?

Accepted Answer

Na+ and Cl- ions are separated and surrounded by hydration shells of water molecules

Question 3

Which of the following best explains why polar molecules dissolve well in water?

Accepted Answer

Polar molecules can form hydrogen bonds or dipole-dipole interactions with water

Question 4

A student adds oil to water and observes that the oil forms droplets on the surface. Which concept best explains this observation?

Accepted Answer

Oil is nonpolar and does not interact favorably with polar water molecules

Question 5

Which of the following statements about hydration shells is correct?

Accepted Answer

Hydration shells are layers of water molecules that surround ions or polar molecules in solution

Question 6

Why do covalent bonds in sugar molecules not break when sugar dissolves in water?

Accepted Answer

Water molecules are not strong enough to break covalent bonds

Question 7

Which of the following best describes a solute?

Accepted Answer

A substance that is dissolved in a solvent

Question 8

Ammonia ($$NH_3) $$dissolves well in water primarily because:

Accepted Answer

It can form hydrogen bonds with water due to its polar N-H bonds

Question 9

Which of the following equations best represents the dissociation of sodium chloride in water?

Accepted Answer

$$NaCl_{(s)} \rightarrow Na^+_{(aq)} + Cl^-_{(aq)}$$

Question 10

A protein is placed in water and does not dissolve completely. Which property of the protein most likely explains this?

Accepted Answer

The protein contains many hydrophobic regions that repel water

Question 11

Which of the following best describes the difference between hydrophilic and hydrophobic substances?

Accepted Answer

Hydrophilic substances dissolve in water, while hydrophobic substances do not

Question 12

Which of the following is NOT a reason why water is a good solvent for ionic compounds?

Accepted Answer

Water molecules are nonpolar and do not interact with ions

Question 13

A student is asked to explain why sugar dissolves in water but oil does not. Which explanation is most accurate?

Accepted Answer

Sugar is polar and forms hydrogen bonds with water, while oil is nonpolar and cannot interact with water

Question 14

Which of the following best describes the interaction between water molecules and ions in solution?

Accepted Answer

Water molecules surround ions, orienting their partially charged ends toward the ions

Question 15

Which of the following statements about Van der Waals forces is correct?

Accepted Answer

They are weak attractive forces that allow nonpolar molecules to interact in nonpolar solvents

Question 16

A solution is made by dissolving 10 g of NaCl in 100 mL of water. Which term best describes NaCl in this context?

Accepted Answer

Solute

Question 17

Which of the following best explains why water molecules are attracted to each other?

Accepted Answer

Water molecules are polar and form hydrogen bonds

Question 18

Which of the following would most likely dissolve in gasoline, a nonpolar solvent?

Accepted Answer

Vegetable oil

Question 19

Which of the following best describes the process of dissolving a covalent molecular solid like sucrose in water?

Accepted Answer

Water molecules surround and separate individual sucrose molecules by forming hydrogen bonds

Question 20

Which of the following is a correct summary of why hydrophobic substances do not dissolve in water?

Accepted Answer

They lack polar or charged regions, so water cannot form hydrogen bonds with them

Properties of Water as a Solvente Lab 2 Part 3 of 3

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