AP Bio Chapter 2 test
Fluorine has an atomic number of 9 and a mass number of 19. How many electrons are needed to complete the valence shell of a fluorine atom?
1
what is the hydrogen ion (H+) concentration of a solution of pH 8?
10^-8 M
what is the maximum number of hydrogen atoms that can be covalently bonded in a molecule containing two carbon atoms
6
carbon dioxide(CO2) is readily soluble in water, according to the equation CO2+H2O-H2CO3. Carbonic acid (H2CO3) is a weak acid. Respiring cells release CO2 into the bloodstream. What will be the effect on the pH of blood as that blood first comes in contact with respiring cells?
Blood pH will decrease sightly
If an atom of sulfur (atomic number 16) were allowed to react with atoms of hydrogen (atomic number 1), which of the molecules below would be formed?
H-S-H
The atomic number of chlorine is 17. The atomic number of magnesium is 12. What is the formula for magnesium chloride?
MgCl2
which of the following ionizes completely in solution and is considered to be a strong base (alkali)?
NaOH
which of the following is (are) not considered to be a weak molecular interaction?
a covalent bond
What results from an unequal sharing of electrons between atoms?
a polar covalent bond
which of the following effects is produced by the high surface tension of water?
a water strider can walk across the surface of a small pond
Liquid water's high specific heat is mainly a consequence of the
absorption and release of heat when hydrogen bonds break and form
How would acidification of seawater affect marine organisms?
acidification would decrease dissolved carbonate concentration and hinder growth of corals and shell-building animals
Buffers are substances that help resist shifts in pH by
both donating H+ to a solution when bases are added and accepting H+ when acids are added
About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements make up approximately 96% of living matter?
carbon, hydrogen, nitrogen, oxygen
water molecules are able to form hydrogen bonds with
compounds that have polar covalent bonds
If the pH of a solution is increased from pH 5 to pH 7, it means that the
concentration of OH- is 100 times greater than what it was at pH 5
what is the difference between covalent bonds and ionic bonds?
covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between atoms
Why is each element unique and different from other elements with respect to its chemical properties?
each element has a unique atomic number
which of the following correctly describes chemical equilibrium?
forward and reverse reactions continue with no effect on the concentration of the reactants and products
which of the following solutions would require the greatest amount of base to be added to bring the solution to neutral pH?
gastric juice at pH 2
which of the following explains most specifically the attraction of water molecules to one another?
hydrogen bond
which type of blood must be broken for water to vaporize?
hydrogen bonds
A strong acid like HCl
ionizes completely in an aqueous solution
A 0.01 M solution of a substance has a pH of 2. What can you conclude about this substance?
it is a strong acid that ionizes completely in water
When two atoms are equally electronegative, they will interact to form
non polar covalent bonds
Hydrophobic substances such as vegetable oil are
non polar substances that repel water molecules
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by
polar covalent bonds
If the cytoplasm of a cell is at pH 7, and the mitochondrial matrix is at pH 8, this means that
the concentration of H+ ion is tenfold higher in the cytoplasm than in the mitochondrial matrix
If a solution has a pH of 7, this means that
the concentration of H+ ions in the water equals the concentration of OH- ions in the water
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
the concentration of hydrogen ions in solution X is 1,000 times as great as the concentration of hydrogen ions in solution Y
The nucleus of a nitrogen atom contains 7 neutrons and 7 protons. Which of the following is a correct statement concerning nitrogen?
the nitrogen atom has a mass number of approximately 14 and an atomic number of 7
Knowing just the atomic mass of an element allows inferences about which of the following?
the number of protons plus neutrons in the element
which of the following statements is true about buffer solutions?
they maintain a relatively constant pH when either acids or bases are added to them
one difference between carbon-12 and carbon-14 is that carbon-14 has
two more neutrons than carbon-12