Exam 1 Flashcards
Which of the following substances is the most soluble in water?
Copper (II) Sulfate (CuSO4)
Which of the following solvents will best dissolve wax, which is a complex mixture of compounds that mostly are CH3-CH2-CH2-CH2-CH2-?
Pentane (CH3CH2CH2CH2CH3)
You double the partial pressure of a gas over a liquid at constant temperature. Which of these statements is then true?
There are twice as many gas molecules in the liquid
Suppose you take a solution and add more solvent, so that the original mass of solvent is doubled. You take this new solution and add more solute, so that the original mass of the solute is doubled. What happens to the molality of the final solution, compared to the original molality?
It is unchanged
Which of the following actions will raise the osmotic pressure of a solution?
Increasing the temperature
Which aqueous solution will have the lowest freezing point?
0.15 m NaCl
A beaker of aqueous nickel sulfide was given to you by the local chemist and you put it on the window sill. After a few days, you notice that the mixture is getting thick toward the bottom. What is the nature of the aqueous nickel sulfate mixture?
It is a suspension
An “emulsifying agent” is a compound that helps stabilize a hydrophobic colloid in a hydrophilic solvent. Which of the following choices is the best emulsifying agent?
CH3(CH2)10COONa
The principal reason for the extremely low solubility of NaCl in benzene (C6H6) is due to:
Weak solvation of Na+ and Cl- by C6H6
The dissolution of water in octane (C8H18) is prevented by:
Hydrogen bonding between water molecules
When argon is placed in a container of neon, the argon spontaneously disperses throughout the neon because:
The dispersion of argon atoms produces an increase in disorder
Hydration is a specific example of the phenomenon known generally as
Solvation
The phrase “like dissolves like” refers to the fact that:
Polar solvents dissolve polar solutes and nonpolar solvents dissolve nonpolar solutes
When solutions of strong electrolytes in water are formed, the ions are surrounded by water molecules. These interactions are described as a case of:
Hydration
Compounds composed of a salt and water combined in definite proportions are known as:
Hydrates
Which of the following substances is more likely to dissolve in water?
HOCH2CH2OH
Which of the following substances is least likely to dissolve in water?
CCl4
Which one of the following substances is more likely to dissolve in CCl4?
CBr4
Which one of the following is most soluble in water?
CH3OH
Pressure has an appreciable effect on the solubility of ____ in liquids
Gases
Which of the following statements is false?
The weaker the attraction between the solute and solvent molecules, the greater the solubility
Which of the following choices has the compounds correctly arranged in order of increasing solubility in water? (least soluble to most soluble)
CCl4
If the partial pressure of oxygen in the air a diver breathes is too great, ______
The urge to breathe is reduced and not enough CO2 is removed from the body
Which of the following concentration units varies with temperature?
Molarity
Of the concentration units below, only ___ uses kg of solvent in its calculation
molality
A solution contains 11% by mass of sodium chloride. This means that ____
100 g of the solution contains 11 g of sodium chloride
As the concentration of a solute in a solution increases, the freezing point of the solution _____ and the vapor pressure of the solution _____
Decreases, decreases
Which of the following liquids will have the lowest freezing point?
aqueous KF (.50m)
A burning splint will burn more vigorously in pure oxygen than in air because ____
Oxygen is a reactant in combustion and concentration of oxygen is higher in pure oxygen than is in air
Of the following, all are valid units for a reaction except ____
mol/L
The kinetics of the reaction below were studied and it was determined that the reaction rate did not change when the concentration of B was tripled. The reaction is _____ order in B.
Zero
A reaction was found to be zero order in A. Increasing the concentration of A by a factor of 3 will cause the reaction rate to _____
remain constant
A reaction A+B—->C obeys the following rate law: Rate= k+[B]^2. If [A] is doubled, how will the rate change?
The rate would remain the same
As the temperature of a reaction is increased, the rate of the reaction increases because the ___
Reactant molecules collide more frequently and with greater energy per collision
In the energy profile of a reaction, the species that exists at the maximum on the curve is called the ____
Activated complex
In general as activation energy increases, reaction rates ____
Goes down regardless of whether the reaction is exothermic or endothermic
The intermediate in the following reaction is
A+B->C+D
B+D->X
D
The equilibrium-constant of the following reaction is Kc=2.1*10^-20. What can be said about this reation?
At equilibrium, the concentration of reactants is much greater than that of products.
