A 48-year-old woman complains of severe polyuria (producing about 0.5 L of urine each hour) and polydipsia (drinking two to three glasses of water every hour). Her urine contains no glucose, and she is placed on overnight water restriction for further evaluation. The next morning, she is weak and confused, her sodium concentration is 160 mEq/L, and her urine osmolarity is 80 mOsm/L. Which of the following is the most likely diagnosis?

#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?

#Question id: 402

#Unit 1. Molecules and their Interaction Relevant to Biology

If the DG'° of the reaction A -> B is –40 kJ/mol, under standard conditions the reaction: