Solutions and States of Matter
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AP Chemistry › Solutions and States of Matter
Calculate the molar solubility of AgBr in 0.050 M AgNO3 at room temperature. The Ksp of AgBr is 5.4 x 10-13.
1.08 x 10-11 M
2.16 x 10-11 M
1.08 M
2.16 M
1.57 x 10-12 M
Explanation
When does a gas behave most like an ideal gas?
At low temperatures, low volume, low intermolecular interactions
At high temperatures, high volume, low intermolecular interactions
At low volumes, high temperatures, and high intermolecular interactions
At high temperature, high volumes, and high intermolecular interactions
At low temperatures, high volume, and low intermolecular interactions
Explanation
The ideal gas law assumes the gas particles are non-interacting and small relative to the size of their container. At high temperatures the gas molecules are moving fast enough to shorten the time scale for any interactions. At high volumes, the molecular size becomes small relative to the size of the container, and the low interactions mean the molecules act more independently.
Would you expect a polar or non polar gas to deviate most from ideal gas behavior?
Non polar gases, because of high dispersion interactions
Polar gases, because of high dipole-dipole interactions
Non polar gases because of reduced overall intermolecular forces
Polar gases because of hydrogen bonding
Both polar and non polar gases behave ideally
Explanation
Polar gases would have increased interactions due to their dipoles that would lead to deviations from ideal gas behavior.
What photon wavelength can promote a transition from the n = 1 (ground state) to the n = 3 (excited state)?
204 nm
306 nm
102 nm
408 nm
1 m
Explanation
;
Under which conditions would you expect Ar to deviate the most from ideal behavior?
200 K and 1 atm
200 K and 10 atm
300K and 5 atm
300K and 10 atm
Ar always behaves ideally
Explanation
The ideal gas law assumes the gas particles are non-interacting and small relative to the size of their container. At 200K (lowest temperature in the list, and the highest pressure). This gives Ar the most time to interact due to molecular speeds and the high pressure implies the molecular size is not insignificant relative to the container.
Calculate the molar solubility of AgBr in 0.050 M AgNO3 at room temperature. The Ksp of AgBr is 5.4 x 10-13.
1.08 x 10-11 M
2.16 x 10-11 M
1.08 M
2.16 M
1.57 x 10-12 M
Explanation
Which of the following compounds is insoluble in water?
Explanation
Unless paired with an alkali metal, carbonate compounds are generally insoluble. Compounds that contain nitrate or an alkali metal will generally be soluble in water, and hydroxides are soluble when paired with heavier alkaline earth metals (such as calcium).
Which of the following will be the precipitate in the following reaction?
2KCl + Ca(OH)2 → 2KOH + CaCl2
Ca
Ca(OH)2
KOH
CaCl2
No precipitate forms
Explanation
Though the solubility of calcium hydroxide, Ca(OH)2, is fairly low, it is a reactant and will not form a precipitate. The solid calcium hydroxide will be added to an aqueous solution of potassium chloride, KCl. During the reaction, the calcium hydroxide will transition to potassium hydroxide (KOH) and calcium chloride (CaCl2), both of which are completely soluble. At the end of the reaction, no precipitate will be observed.
Consider the following balanced equation for the solubility of barium hydroxide in an aqueous solution.
What is the equilibrium expression for the balanced reaction?
Explanation
When writing the equilibrium expression for an insoluble salt, remember that pure solids and liquids are not included in the expression. Also, the coefficients for the compounds in the balanced reaction become the exponents for the compounds in the equilibrium expression.
Given a generalized chemical reaction, we can determine the equilibrium constant expression.
In our reaction, the reactant is a pure solid and is not included in the equilibrium calculation.
Consider the typical phase diagram of a compound given below.

Which of the following lines or points on the diagram represents a situation in which the rate of vaporization of the compound is equal to its rate of condensation?
Line C
Line A
Line B
Point D
None of these
Explanation
In this question, we're presented with a phase diagram and are asked to determine where on the graph the rate of vaporization equals the rate of condensation.
First, it's important to realize that when the rate of vaporization and condensation are equal, we have an equilibrium of liquid and gas phases. In other words, for a given temperature and pressure, the rate at which the liquid evaporates into a gas is exactly equal to the rate at which the gas condenses into a liquid.
On a phase diagram, the area of the upper left portion of the diagram represents the solid state. The middle portion of the diagram represents the liquid state. The bottom and right most part of the diagram represents the gas phase.
Furthermore, each line on the diagram represents the specific combination of temperature and pressure in which a given compound will exist in equilibrium between two phases. The point where all three lines intersect, however, represents the triple point. This tells us the temperature and pressure in which the compound will exist in an equilibrium between all three states.
Because we are looking for the equilibrium line that represents equilibrium of vaporization and condensation, we want the line that separates the liquid portion of the diagram from the gas portion. Based on the identification of regions on the diagram discussed above, that would be line C as shown in the diagram. Line A represents equilibrium between solid and gas (sublimation rate = deposition rate). Line B represents equilibrium between solid and liquid (melting rate = freezing rate).