Exam 3: Water and Life

A small birthday candle is weighed, then lighted and placed beneath a metal can containing 100 mL of water. Careful records are kept as the temperature of the water rises. Data from this experiment are shown on the graph. What amount of heat energy is released in the burning of candle wax?

Hydrogen bonding in water is a result of

Use the following figure to answer the questions below. -How many grams of the compound in the figure above would be required to make 2.5 L of a 1 M solution? (carbon = 12, oxygen = 16, hydrogen = 1)

If the pH of a solution is decreased from 9 to 8, it means that the

Use the following information to answer the questions below. You live in Atlantic Canada and you are Skyping a friend in Manitoba. You are both complaining about the weather as both regions are being subjected to the same arctic air mass. As you discuss it, however, it becomes clear that she is experiencing a bitter cold that you are not. You realize that you had pretty much the same conversation last summer when it was much hotter in Manitoba than at home. -This phenomenon is due to

The partial negative charge in a molecule of water occurs because

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

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

Why does ice float in liquid water?

Use the following information to answer the questions below. You live in Atlantic Canada and you are Skyping a friend in Manitoba. You are both complaining about the weather as both regions are being subjected to the same arctic air mass. As you discuss it, however, it becomes clear that she is experiencing a bitter cold that you are not. You realize that you had pretty much the same conversation last summer when it was much hotter in Manitoba than at home. -A slice of pizza has 2092 kJ. 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.)

Use the following information to answer the questions below. You live in Atlantic Canada and you are Skyping a friend in Manitoba. You are both complaining about the weather as both regions are being subjected to the same arctic air mass. As you discuss it, however, it becomes clear that she is experiencing a bitter cold that you are not. You realize that you had pretty much the same conversation last summer when it was much hotter in Manitoba than at home. -We can be sure that a mole of table sugar and a mole of vitamin C are equal in their

Water molecules are able to form hydrogen bonds with

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

You have a freshly prepared 1 M 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?

Identical heat lamps are arranged to shine on identical containers of water and methanol (wood alcohol), so that each liquid absorbs the same amount of energy minute by minute. The covalent bonds of methanol molecules are nonpolar, so there are no hydrogen bonds among methanol molecules. Which of the following graphs correctly describes what will happen to the temperature of the water and the methanol?

If the cytoplasm of a cell is at pH 7, and the mitochondrial matrix is at pH 8, this means that

What is the pH of a solution with a hydroxyl ion [OH⁻] concentration of 10⁻¹² ᴹ?

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 into the bloodstream. What will be the effect on pH of blood as that blood first comes in contact with respiring cells?

A beaker contains 100 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 results of this mixing?

The biological significance of water being its densest at 4°C is that