MB Chp. 3

The unequal sharing of electrons within a water molecule makes the water molecule _____. have a low surface tension change easily from a liquid to gaseous form polar hydrophobic ionic

polar

In this molecule, what type of bond is found between the oxygen and hydrogens? polar covalent nonpolar covalent hydrophilic hydrophobic ionic

polar covalent

Because of ocean acidification, the price of which of the following foods is most likely to increase? squid swordfish shellfish tuna

shellfish

Most acid precipitation results from the combination of _____ with water in the atmosphere, forming strong acids that fall with rain or snow. ammonium carbon dioxide buffers sulfur oxides and nitrogen oxides ozone

sulfur oxides and nitrogen oxides

A pH of 6 is how many times more acidic than a pH of 9? 3 30 100 300 1,000

1,000

What is the hydroxide ion concentration of the lake described in question 5? 10-7 M 10 M 10-4 M 10-10 M 10-14M

10^-10M

Measurements show that the pH of a particular lake is 4.0. What is the hydrogen ion concentration of the lake? 10-10 M 104 M 4.0 M 4% 10-4 M

10^-4M

Factory smoke has led to acid rain that lowered the pH of a lake to 5.0. What is the H+ concentration in the lake? log (5) M 5% 5.0 M 105 M 10- 5 M

10^-5M

How much carbon dioxide from the atmosphere is absorbed by the oceans on a daily basis? 2 million metric tons 20 million metric tons 70 million metric tons 10 billion metric tons

20 million metric tons

If the molecular mass of a carbon atom is 12, the mass of a hydrogen atom is 1, and the mass of an oxygen atom is 16 daltons, how many molecules does one mole of table sugar (sucrose; C12H22O11) contain? 6.02 x 1023 6.02 x 1023/342 (6.02 x 1023)(342) 45 342

6.02X10^23

Select the statement that best describes a buffer. A buffer resists change in pH by accepting hydrogen ions when acids are added to the solution and donating hydrogen ions when bases are added. A buffer causes acidic solutions to become alkaline, and alkaline solutions to become acidic. A buffer stabilizes the pH of a solution by preventing acids or bases from dissociating. A buffer prevents the pH of a solution from changing when an acid or base is added. Buffered solutions are always neutral, with a pH of 7.

A buffer resists change in pH by accepting hydrogen ions when acids are added to the solution and donating hydrogen ions when bases are added.

Which of the following are consequences of ocean acidification? Select all that apply. Clams, mussels, lobsters, and shrimp are not able to form strong enough shells. Ocean temperatures are dropping. Animals in the oceans cannot get enough oxygen. Corals and coral reefs are not able to form their hard skeletons.

Clams, mussels, lobsters, and shrimp are not able to form strong enough shells. Corals and coral reefs are not able to form their hard skeletons.

Which one of these bonds are weakest?

Hydrogen Bonds are weaker than covalent bonds because they do not involve sharing of electrons, and they are weaker than ionic bonds because they involve the attraction of partial (not full) opposite charges.

How are oyster larvae affected by ocean acidification? Oyster larvae cannot grow shells in acidified ocean waters. Oyster larvae are killed by carbon dioxide in acidified ocean waters. Acidified ocean waters are too cloudy for photosynthesis to occur under water. Acidified ocean waters favor fish that eat oyster larvae.

Oyster larvae cannot grow shells in acidified ocean waters.

Your tank of swamp fish needs a pH of 5, and the pH is 7 at present. What should you do to the H+ concentration? Cut it in half. Reduce it to 1/100 of its present value. Raise it to 100 times its present value. Double it. Raise it to 200 times its present value.

Raise it to 100 times its present value.

Your tank of alkali fish needs a pH of 8, and the pH is 6 at present. What should you do to the H+ concentration? Reduce it to 1/200 times its present value. Reduce it to 1/100 of its present value. Cut it in half. Double it. Raise it to 100 times its present value.

Reduce it to 1/100 of its present value.

Why isn't this insect drowning? The insect is swimming. The insect is flying just above the water surface. It is difficult to change the temperature of water. The insect is very light. Surface tension.

Surface tension

What conditions must be met in order for an aqueous solution to be called "neutral"? The hydronium ion concentration is greater than the hydroxide ion concentration. The hydroxide ion concentration is greater than the hydronium ion concentration. There are no hydronium or hydroxide ions present in the solution. The concentrations of hydronium and hydroxide ions are equal. None of the above.

The concentrations of hydronium and hydroxide ions are equal.

Sharing of electrons in water, partial charges

The image on the left shows the unequal sharing of electrons in a water molecule. Notice that the electrons are pulled toward the oxygen atom, which is more electronegative than a hydrogen atom, resulting in a partial negative charge (δ−) on the oxygen atom and a partial positive charge (δ+) on each hydrogen atom.

Electronegativity of water

Water is electronegative polar, partial negative to partial negative

What is the main reason that the oceans are becoming more acidic? the dumping of garbage and sewage into the oceans large crude oil spills in the oceans absorption by the oceans of carbon dioxide generated by burning fossil fuels fertilizer runoff in major rivers flowing into the oceans

absorption by the oceans of carbon dioxide generated by burning fossil fuels

Which property of water allows a paper towel to pick up a puddle of water? adhesion of water molecules to other kinds of molecules water's high surface tension water's high heat of vaporization

adhesion of water molecules to other kinds of molecules

Many of water's emergent properties, such as its cohesion, its high specific heat, and its high heat of vaporization, result from the fact that water molecules _____. are very small tend to repel each other are in constant motion are extremely large are attracted to each other by partial negative and positive charges on the oxygen and hydrogen atoms, respectively

are attracted to each other by partial negative and positive charges on the oxygen and hydrogen atoms, respectively

What is the chemical reaction responsible for the oceans becoming more acidic? methane reacts with seawater, forming carbon dioxide carbon dioxide reacts with seawater, forming nitric acid carbon dioxide reacts with seawater, forming sulfuric acid carbon dioxide reacts with seawater, forming carbonic acid

carbon dioxide reacts with seawater, forming carbonic acid

The tendency of an atom to pull electrons toward itself is referred to as its _____. ionic potential covalency tonicity electronegativity polarity

electronegativity

Each water molecule is joined to _____ other water molecules by ____ bonds. four ... polar covalent four ... hydrogen two ... polar covalent three ... ionic two ... hydrogen

four, hydrogen

Because organisms are made primarily of water, they resist rapid temperature changes. This useful quality is based on water's _____. ability to form colloids cohesion high specific heat buffering activity lower density in the solid phase

high specific heat

Water molecules have a polarity, which allows them to be electrically attracted to other water molecules and other polar molecules by weak chemical bonds known as _____. nonpolar covalent bonds ionic bonds polar covalent bonds Van der Waals interactions hydrogen bonds

hydrogen bonds

An acid is a substance that _____. increases the hydrogen ion concentration of an aqueous solution contains hydrogen forms covalent bonds with other substances is a versatile solvent reduces the hydrogen ion concentration of a solution

increases the hydrogen ion concentration of an aqueous solution

Which answer is a true statement about pH values? pH is important in life mainly because it affects the cohesion of water. Pure water has a pH of 0. Stomach juice has a high pH. A high pH corresponds to a high H+ concentration. None of the above.

none of the above

Which property of water allows dogs to cool themselves by panting? water's high surface tension water's high heat of vaporization the formation of covalent bonds between water molecules

water's high heat of vaporization

Which property of water allows a water strider to walk on water? the formation of covalent bonds between water molecules water's high surface tension adhesion of water molecules to other kinds of molecules

water's high surface tension

Which of the following is a hydrophobic material? pasta wax paper table salt sugar

wax