water chapter 3 ap bio

What is [-OH] for coffee?

1 x10^-9

Assume that acid rain has lowered the pH of a particular lake to pH 4.0. What is the hydroxyl ion concentration of this lake

1 × 10-10 mol of hydroxyl ion per liter of lake water

what is the hydroxide ion concentration of the lake described in question 5?

10-10M

Measurements show that the pH of a particular lake is 4.0. What is the hydrogen ion concentration of the lake?

10-4M

The nutritional information on a cereal box shows that one serving of a dry cereal has 200 kilocalories. If one were to burn one serving of the cereal, the amount of heat given off would be sufficient to raise the temperature of 20 kg of water how many degrees Celsius

10.0°C

One liter of a solution pH 9 has how many more hydroxyl ions (OH -) than 1 L of a solution of pH 4

100,000 times more

Consider two solutions labeled "A" and "B". Solution A has a pH of 6 and solution B has a pH of 9. Solution A has a hydrogen ion concentration that is...

1000 times higher than that of solution B

a slice of pizza has 500 kcal. if we could burn the pizza and use all the heat to warm a 50-L container of cold water, what would be the approximate increase in the temperature of the water?

10°

the molecular mass of methane (CH4) is 16 daltons. If you carefully measure out 1 mole if methane, how much would it weigh?

16 grams

At what temperature is water at its densest?

4°C

The molecular weight of water is 18 daltons. What is the molarity of 1 liter of pure water

55.6M

You have a freshly-prepared 1M solution of glucose in water. You carefully pour out a 100 mL sample of that solution. How many glucose molecules are included in that 100 mL sample

6.02 × 1024

How many grams of acetic acid (C2H4O2) would you use to make 10L of a 0.1 M aqueous solution of acetic acid?

60g

You have two beakers. One contains a solution of HCl at pH = 1.0. The other contains a solution of NaOH at pH = 13. Into a third beaker, you slowly and cautiously pour 20 mL of the HCL and 20 mL of the NaOH. After complete stirring, the pH of the mixture will be

7

One mole (mol) of a substance is

A and D (6.02 x 10^23 molecules of the substance, the molecular mass of the substance is expressed in grams)

why is water such an excellent solvent

As a polar molecule, it can surround and dissolve ionic and polar molecules

Carbon dioxide (CO2) is readily soluble in water, according to the equation CO2 + H2O → H2CO3. Carbonic acid (H2CO3) is a weak acid. Respiring cells release CO2. What prediction can we make about the pH of blood as that blood first comes in contact with respiring cells

Blood pH will decrease slightly

Buffers are substances that help resist shifts in pH by

Both B and D (donating H+ to a solution when they have been depleted, accepting H+ when the are in excess)

Which of the following ionizes completely in solution and is considered to be a strong acid

HCl

Why does ice float in liquid water

Hydrogen bonds stabilize and keep the molecules of ice farther apart than the watermolecules of liquid water

Which of the following takes place as an ice cube cools a drink

Kinetic energy in the drink decreases

Which of the following statements is completely correct

NH3 is a weak base (alkali), and HCl is a strong acid

You have two beakers; one contains pure water, the other contains pure methanol (wood alcohol). The covalent bonds of methanol molecules are nonpolar, so there are no hydrogen bonds among methanol molecules. You pour crystals of table salt (NaCl) into each beaker. Predict what will happen

NaCl crystals will dissolve readily in water but will not dissolve in methanol

Consider two solutions: solution X has a pH of 4; solution Y has a pH of 7. From this information, we can reasonably conclude that

None of the other answer choices correctly describes these solutions

Many mammals control their body temperature by sweating. Which property of water is most directly responsible for the ability of sweat to lower body temperature?

The absorption of heat by the breaking of hydrogen bonds

Which of the following statements is true about buffer solutions

They maintain a relatively constant pH when either acids or bases are added to them

Thus,H2CO3 ↔ HCO3- + H+ If the pH of the blood increases, one would expect

a decrease in the concentration of H2CO3 and an increase in the concentration of H2O

A given solution contains 0.0001(10-4) moles of hydrogen ions [H+] per liter. Which of the following best describes this solution

acidic: H+ donor

What accounts for the movement of water up the vessels of a tall tree?

cohesion, hydrogen bonding, adhesion, and hydrophilic cell walls

Which has the highest molar concentration of H+? cola, orange juice, beer, coffee, or human blood

cola

If the pH of a solution is increased from pH 5 to pH 7, it means that the

concentration of OH- is 100 times greater than what it was at pH 5

Ice floats because

hydrogen bonding spaces the molecules farther apart, creating a less dense structure

The bonds that are broken when water vaporizes are

hydrogen bonds between water molecules

A solution contains 0.0000001(10-7) moles of hydroxyl ions [OH-] per liter. Which of the following best describes this solution

neutral

We can be sure that a mole of table sugar and a mole of vitamin C are equal in their

number of molecules

what sort of molecules dissolve readily in water?

polar and charged molecules

Which of the following solutions has the greatest concentration of hydroxyl ions [OH-]

seawater at pH 8

A burn from steam at 100 degree C is more severe than a burn from boiling water because

steam releases a great deal of heat as it condenses on the skin

Thus,H2CO3 ↔ HCO3- + H+ If the pH of the blood drops, one would expect

the HCO3- to act as a base and remove excess H+ with the formation of H2CO3

Pure, freshly-distilled water has a pH of 7. This means that

the concentration of H+ ions in the water equals the concentration of OH- ions in thewater.

Climates tend to be moderate near large bodies of water because..

the high specific heat of water helps to moderate air temps

the molarity of a solution is equal to

the number of moles of solute in 1 liter of solution

Evaporative cooling is a result of

the reduction in the average kinetic energy of a liquid after energetic water molecules enter the gaseous state

Temperature usually increases when water condenses. Which behavior of water is most directly responsible for this phenomenon

the release of heat by the formation of hydrogen bonds

Research indicates that acid precipitation can damage living organisms by

washing away certain mineral ions that help buffer soil solution and are essentialnutrients for plant growth

Which of the following is a hydrophobic material?

wax