Question 1

Which property of water is primarily responsible for the ability of insects to walk on its surface?

Accepted Answer

High surface tension due to cohesion

Question 2

A solution is prepared by dissolving 58 g of NaCl (molecular mass = 58 g/mol) in enough water to make 1 liter of solution. What is the molarity of NaCl in this solution?

Accepted Answer

$$1\ \mathrm{M}$$

Question 3

Which of the following best explains why ice floats on liquid water?

Accepted Answer

Hydrogen bonds in ice create a crystalline lattice that is less dense than liquid water

Question 4

What is the pH of a solution with a hydrogen ion concentration of $$[H^+] = 1.0 	imes 10$$^{-4}$$\ \mathrm{M}$$?

Accepted Answer

$$4$$

Question 5

Which of the following substances would NOT dissolve well in water?

Accepted Answer

Vegetable oil

Question 6

A buffer solution contains a weak acid and its corresponding base. What is the main function of a buffer in biological systems?

Accepted Answer

To maintain a constant pH by minimizing changes in $$[H^+]$$ and $$[OH^-]$$

Question 7

Which of the following equations correctly represents the relationship between pH and hydrogen ion concentration?

Accepted Answer

$$\mathrm{pH} = -\log [H^+]$$

Question 8

Ocean acidification is primarily caused by which process?

Accepted Answer

Increased carbon dioxide ($$CO_2) $$dissolving in seawater forming carbonic acid

Question 9

If you have 0.5 moles of NaCl dissolved in 1 liter of water, what is the molarity of the solution?

Accepted Answer

$$0.5\ \mathrm{M}$$

Question 10

Which property of water allows it to absorb and release large amounts of heat with only slight changes in its own temperature?

Accepted Answer

High specific heat

Question 11

A student adds 0.0235 M HCl to water. What is the pOH of the resulting solution? (Use $$\mathrm{pOH} = 14 - \mathrm{pH}$$ and $$\mathrm{pH} = -\log[H^+])$$

Accepted Answer

$$2.371$$

Question 12

Which of the following best describes a hydrophobic molecule?

Accepted Answer

It contains many nonpolar bonds and does not dissolve in water

Question 13

A solution is made by dissolving 42.23 g of NH$$_4Cl ($$molar mass = 53.50 g/mol) in enough water to make 500.0 mL of solution. What is the molarity of NH$$_4Cl in $$this solution?

Accepted Answer

$$1.58\ \mathrm{M}$$

Question 14

Which of the following is NOT one of the four emergent properties of water that contribute to Earth's suitability for life?

Accepted Answer

High reactivity with nonpolar molecules

Question 15

What happens to the concentration of carbonate ions in seawater as ocean acidification increases?

Accepted Answer

It decreases, making it harder for organisms to build shells

Question 16

Which of the following best describes the difference between an acid and a base in aqueous solution?

Accepted Answer

An acid increases $$[H^+]$$ and a base decreases $$[H^+]$$

Question 17

Which of the following is a real-world consequence of water's high specific heat?

Accepted Answer

Stable climates and minimized temperature fluctuations near large bodies of water

Question 18

A solution contains $$3.60 	imes 10$$^{-3}$$ moles of NaOH and 5.95$$ 	imes $$10^{-4}$$ moles of HCl in 1.00 L of water. What is the pH of the solution after neutralization? (Assume complete reaction: $$\mathrm{NaOH} + \mathrm{HCl} ightarrow \mathrm{NaCl} + \mathrm{H_2O})$$

Accepted Answer

$$11.76$$

Question 19

Which of the following best explains why water is a versatile solvent?

Accepted Answer

Water's polarity allows it to form hydration shells around ions and polar molecules

Question 20

Which of the following is a direct effect of evaporative cooling in living organisms?

Accepted Answer

Stabilization of internal temperature during sweating

Water and Life: Properties, Chemistry, and Biological Importance

Guida di studio - Domande di pratica

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