Exam 2: Water and Carbon: the Chemical Basis of Life

You have two beakers. One contains pure water; the other contains pure methanol (wood alcohol). The covalent bonds of methanol molecules are nonpolar, so there are no hydrogen bonds among methanol molecules. You pour crystals of table salt (NaCl) into each beaker. Predict what will happen.

Which of the following is TRUE of carbon?

A strong acid like HCl ________.

The complexity and variety of organic molecules is due to ________.

Which one of the following pairs of neutral atoms would be most likely to form ions and thus an ionic bond?

Refer to the following figure to answer the questions below. Refer to the figure above (first three rows of the periodic table). What element has properties most similar to carbon?

Knowing the atomic mass of an element allows inferences about which of the following?

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

What does it mean to say a system's energy is equal to zero?

A covalent chemical bond is one in which ________.

You need to represent a molecule to best illustrate the relative sizes of the atoms involved and their interrelationships. Which representation would work best?

Why are some reactions exothermic?

The first chemicals that provided potential energy on Earth may have been formaldehyde and hydrogen cyanide. While these were produced by sunlight-driven reactions, they also occurred around deep-sea vents. If the first organisms on Earth evolved around these vents, the first life on Earth was ________.

A carbon atom is most likely to form what kind of bond(s) with other atoms?

Carbon-12 is the most common isotope of carbon and has a mass number of 12. However, the average atomic mass of carbon found on a periodic table is slightly more than 12 daltons. Why?

A solution with a pH of 5 has how many more protons in it than a solution with a pH of 7?

Which of the following correctly describes a reaction that has reached chemical equilibrium?

Why do chemical reactions tend to speed up when the concentration of the reactants is increased?

Why are hydrocarbons insoluble in water?

Why is carbon so important in biology?