Exam 3: Water and Life

One of the buffers that contribute to pH stability in human blood is carbonic acid (H₂CO₃). Carbonic acid is a weak acid that, when placed in an aqueous solution, dissociates into a bicarbonate ion (HCO₃-) and a hydrogen ion (H⁺). (See figure.) If the pH of blood drops, one would expect ________.

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

Thermal energy of the water in a bathtub is ________ than in freshly brewed coffee because of its ________.

A beaker contains 100 millilitres (mL) of NaOH solution at pH = 13. A technician carefully pours into the beaker 10 mL of HCl at pH = 1. Which of the following statements correctly describes the result of this mixing?

Which of the following can be attributed to water's high specific heat?

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

A 0.01 M solution of a substance has a pH of 2. What can you conclude about this substance?

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? (Note: A litre of cold water weighs about 1 kg.)

To act as an effective coolant in a car's radiator, a substance has to have the capacity to absorb a great deal of heat. You have a reference book with tables listing the physical properties of many liquids. In choosing a coolant for your car, which table would you check first?

The loss of water from a plant by transpiration cools the leaf. Movement of water in transpiration requires both adhesion to the conducting walls and wood fibres of the plant and cohesion of the molecules to each other. A scientist wanted to increase the rate of transpiration of a crop species to extend its range into warmer climates. The scientist substituted a nonpolar solution with an atomic mass similar to that of water for hydrating the plants. What do you expect the scientist's data will indicate from this experiment?

You have a freshly prepared 0.1 M sucrose (molecular mass 342) solution, which means ________.

Two moles of the compound in the figure would weigh how many grams? (Note: The atomic masses, in daltons, are approximately 12 for carbon, 1 for hydrogen and 16 for oxygen.)

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

The molar mass of glucose is 180 grams per mole (g/mol). Which of the following procedures should you carry out to make a 1 M solution of glucose? In 0.8 litre (L) of water, dissolve ________.

Water molecules can form hydrogen bonds with ________.

Which of the following is considered to be a strong base (alkali)?

The partial negative charge at one end of a water molecule is attracted to the partial positive charge of another water molecule. What is this attraction called?

A dietary Calorie equals 1 kilocalorie. One kilocalorie equals ________.

A solution with a pH of 2 has how many more protons in it than a solution with a pH of 4?

Which of the following statements is true about buffer solutions?