Chemistry Chapter 7
If you need 3.01x10^23 molecules of surcose, how many liters of a 4.00 molar solution would you need?
0.125 L
Which of the following solutions is the most concentrated?
0.5 L of a 3 molar solution
How many moles of sugar, C12H22O11, are there in 200. grams?
0.585 moles
How many grams of sugar (sucrose) are there in 5.0 liters of sugar water that has a concentration of 0.50 grams per liter of solution?
2.5 g
If the solubility of a compound is 30 grams per liter, how much solid is left undissolved if you mix 30 g of the compound in 0.33 L of solution?
20 g
A solid has a solubility at room temperature of 78 grams per liter. If 1.0 L of a heated solution containing 100. g of solute is cooled to room temperature, how much solid is formed?
22 g
How many molecules of sucrose are in 0.500 L of a 1.00 molar solution of sucrose?
3.01 x 10^23 molecules of surcose
If the solubility of a compound is 72 grams per liter at a given temperature, how many grams of the compound will dissolve in 0.50 liters at the same temperature?
36 g
What is the molarity when water is added to 2 moles of sodium chloride to make 0.5 liter of solution?
4 M
How many grams of sodium chloride are needed to make 15 L of a solution that has a concentration of 3.0 g per liter of solution?
45 g
A 1 molar solution of sucrose (Formula Weight 342.6 g/mol) solution contains ________.
6.02 x 10^23 molecules of surcose
How many molecules of sucrose are in 0.5 00L of a 2.00 molar solution of sucrose?
6.02 x 10^23 molecules of surcose
Which of the following describes an aqueous solution?
A mixture of some compound dissolved in water.
A soap molecule is...?
A molecular with both a polar and nonpolar part
What is a hydrogen bond?
A special type of dipold-dipole attraction involving hydrogen bound to a highly electronegative atom
How can you tell whether a sugar solution is saturated or not?
Add more sugar. If it does not dissolve after mixing, the solution is saturated.
Which has the most atoms?
All have the same number of atoms
In which of the following molecules will water induce a temporary dipole?
All of them
Account for the observation that ethyl alcohol, C2H5OH, dissolves readily in water but dimethyl ether, C2H6O, which has the same number and kinds of atoms, does not.
Because dimethyl either lacks an -OH group, it is significantly less polar than is ethyl alcohol and is not readily soluble in water.
What is the main difference between a dipole-dipole interaction and a dipole-induced dipole interaction?
Both are similar, but one involves a temporary dipole created by a permanent dipole
Chlorine is a gas at room temperature, but bromine is a liquid. Explain.
Bromine atoms are larger and this makes the formation of induced dipole-induced dipole attractions more favorable
Which of the following would have the weakest induced dipole-induced dipole interactions?
C6H14
Which of the following would have the lowest melting point?
CF4
Hard water contains excessive amounts of...?
Calcium ions
The separation of charges within a polar molecule is called a(n) ________.
Dipole
Which of the following is most likely to have the weakest induced dipole-induced dipole interaction?
F2
Which of the following molecules is most likely to show a dipole-dipole interaction?
H-C-C-H
Which of the following molecules would you expect to be the most strongly attracted to a Cl- ion?
H-F
Which of the following molecules would you expect to be the least attracted to a Na+ ion?
H3C-CH3
Which of the following would have the highest boiling point?
I2
An inventor claims to have developed a new perfume that lasts a long time because it doesn't evaporate. Comment on this claim.
In order to smell something, the molecules must evaporate and reach your nose. If the new perfume doesn't evaporate, it will not have an odor.
Why are the melting temperatures of most ionic compounds far greater than the melting temperatures of most covalent compounds?
Ionic bonds are so much stronger than the intermolecular attractions between covalently bonded compounds
How is the solubility of a solid affected by temperature?
It depends on the solid
What statement best describes a mole?
It is a very large number chemists use to count atoms or molecules
Which of the following describes the term concentration?
It is the amount of solute in a given amount of solution
Under which of the following conditions would you expect the highest solubility of oxygen gas in water?
Low temperature and high pressure above the solution
A student is told to use 10.00 grams of sodium chloride to make an aqueous solution that has a concentration of 1.00 grams of sodium chloride per liter of solution. How much water will she use in making this solution?
Slightly less that 10 L
Fish don't live very long in water that has just been boiled and brought back to room temperature. Suggest why.
The boiling process removes most of the air that was dissolved in the water. Upon cooling the water is void of its usual air content, hence the fish drown.
If an ionic bond is stronger than a dipole-dipole interaction, how can water dissolve an ionic compound?
The ion-dipole interactions of a bunch of water molecules gang up on the strong ionic bond and pull it into the solution
What property primarily determines the effect of temperature on the solubility of gas molecules?
The kinetic energy of the gas
Why are ion-dipole attractions stronger than dipole-dipole attractions?
The magnitude of the electric charge associated with an ion is much greater.
Which of the following accurately describes osmosis?
The more concentrated solution absorbs water from the less concentrated solution
What is molarity?
The number of moles of solute per liter of solution
What happens if you were to place a dilute solution that is in a bag made of a semipermeable membrane and were to then suspend it in a very concentrated solution?
The size of the suspended bag would decrease
What happens if you were to place a concentrated solution into a bag made of a semipermeable membrane and were to then suspend it in a very dilute solution?
The size of the suspended bag would increase.
What is happening at the molecular level when a polar molecule like water interacts with a typical sodium ion?
The water molecule aligns such that the oxygen interacts with the sodium.
During osmosis...?
The water moves into the concentrated solution faster than it leaves.
Would you expect to find more dissolved oxygen in polar or tropical ocean waters? Why?
There would be more dissolved oxygen in the polar oceans because the solubility of oxygen in water decreases with increasing temperature.
Which of the following solutions is the most dilute?
They all have the same concentration
A saturated solution of compound X in water has a greater concentration than does a saturated solution of compound Y. Does it follow that compound X is also more soluble in water?
Yes, compound X is more soluble than is compound Y because a greater concentration in water can be obtained.