#Question id: 396
#Unit 1. Molecules and their Interaction Relevant to Biology
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?
#Question id: 397
#Unit 1. Molecules and their Interaction Relevant to Biology
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 fibers 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?
#Question id: 398
#Unit 1. Molecules and their Interaction Relevant to Biology
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 ________.
#Question id: 399
#Unit 1. Molecules and their Interaction Relevant to Biology
Calculate the pH of a 1 L solution containing 0.100 M formic acid and 0.100 M sodium formate before and after the addition of 1.00 mL of 5.00 M NaOH. How much would the pH change if the NaOH were added to 1.00 L of pure water? (pKa for formic acid is 3.75)
#Question id: 400
#Unit 1. Molecules and their Interaction Relevant to Biology
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 ________.
#Question id: 401
#Unit 1. Molecules and their Interaction Relevant to Biology
.Which of the following graphs describes the relationship between [H3O+] and pH?