Exam 3: Water and Life

Identical heat lamps are arranged to shine on two identical containers, one containing water and one 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, then the concentration of H⁺ ions ________.

Consider the following reaction at equilibrium: CO₂ + H₂O H₂CO₃. What would be the effect of adding additional H₂O?

A solution contains 0.0000001 (10-7) moles of hydrogen ions [H⁺] per litre. Which of the following best describes this solution?

How would acidification of seawater affect marine organisms? Acidification of seawater would ________.

Geraldton, Morowa and Mount Magnet in Western Australia are at about the same latitude, but Mount Magnet has much hotter summers and much colder winters than Geraldton. Why?

Melting of ice and thus reduced feeding opportunities for polar bears is occurring because of the ________.

Which of the following is a hydrophobic material?

Rank, from low to high, the pH of blood, stomach acid, and urine.

Which of the following graphs describes the relationship between [H₃O⁺] and pH?

Based on your knowledge of the polarity of water molecules, the solute molecule depicted is most likely ________.

Carbon dioxide (CO₂) is readily soluble in water, according to the equation CO₂ + H₂O ↔ H₂CO₃. Carbonic acid (H₂CO₃) is a weak acid. If CO₂ is bubbled into a beaker containing pure, freshly distilled water, which of the following graphs correctly describes the results?

Which of the following effects can occur because of the high surface tension of water?

As the [H₃O⁺] of the solution decreases, the [OH^-] ________.

How many grams of the compound in the figure are required to make 1 litre of a 0.5 M solution? (Note: The atomic masses, in daltons, are approximately 12 for carbon, 1 for hydrogen and 16 for oxygen.)

Water has many exceptional and useful properties. Which is the rarest property among compounds?

The partial negative charge in a molecule of water occurs because ________.

Cohesion, surface tension, and adhesion are the properties of water molecules that ________.

What is the pH of a solution with a hydroxyl ion (OH-) concentration of 10-10 M?

Sulphur is in the same column of the periodic table as oxygen, but has electronegativity similar to carbon. Compared to water molecules, molecules of H₂S will ________.