Chemistry Final
What three factors do you need to know in order to calculate the heat change of a chemical reaction in a calorimeter?
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What is an electrolyte?
Anything that forms ions when dissolved in water
A solution has which of the following properties? A. The top layer is different in composition than the bottom layer. B. The average diameter of its solute particles usually is less than 1 nm C. Gravity separates it's parts D. A filter can remove the solute.
B
A solution is a mixture A. That is heterogeneous B. From which the solute can be filtered C. That has the same properties throughout D. In which a solid solute is always dissolved in a liquid solvent.
B
An electric current can be best conducted by__. A. Methane gas B. A salt solution C. Rubbing alcohol D. A sugar solution
B
How does shaking or stirring a mixture of solute and solvent affect a solution? A. It decreases the solubility of the solute B. It increases the rate of dissolving. C. It increases the solubility of the solute. D. It decreases the rate of dissolving.
B
How does the surface tension of water compare with the surface tensions of most other liquids? A. It is lower. B. It is higher C. It is higher only when a surfactant is added D. It is about the same.
B
If adding a crystal of the solute to an aqueous solution causes many particles to come out of the solution, the original solution was___. A. Saturated B. Supersaturated C. Unsaturated D. An emulsion
B
What causes water's low vapor pressure? A. Covalent bonding B. Hydrogen bonding C. Dispersion forces D. Ionic attractions
B
What happens to the solubility of a gas in a liquid if the partial pressure of the gas above the liquid decreases? A. The solubility remains the same. B. The solubility decreases C. The solubility increases. D. The solubility cannot be determined
B
What happens when energy is changed from one form to another? A. Some of the energy is lost entirely. B. All of the energy can be accounted for C. A physical change to a substance occurs D. All of the energy is changed to a useful form.
B
What is the Molarity of a solution containing 7.0 moles of solute in 569 mL of solution? A. 4.0 M B. 12M C. .081 M D. 81 M
B
What is the freezing point of a solution of .5 mol of LiBr in 500 g of water? (Kf=1.86 degrees Celsius/m) A. -5.58 degrees Celsius B. -1.86 degrees Celsius C. -7.44 degrees Celsius D. -3.72 degrees Celsius
B
What mass of sucrose C12H22O11, is needed to make 500 mL of a .200M solution? A. 100 g B. 34.2 g C. 17.1 g D. 68.4 g
B
The bonds between the hydrogen and oxygen atoms in a water molecule are__. A. Hydrogen bonds B. Ionic bonds C. Polar covalent bonds D. Non polar covalent bonds.
C
Which of the following is a Colligative property of a solution? A. Freezing point increase B. Vapor pressure increase C. Boiling point elevation D. Melting point elevation
C
Which of the following substances dissolves most readily in gasoline? A. NaBr B. HCl C. CH4 D. NH3
C
Which of the following substances is an electrolyte? A. Cl2 B. CCl4 C. MgCl2 D. CH4
C
Which of the following substances is the most soluble in water? A. Bromine B. Carbon C. Sodium chloride D. Methane
C
An emulsion is which type of mixture? A. Suspension B. Gaseous C. Solution D. Colloid
D
Colligative properties depend upon the__. A. Nature of the solvent B. Freezing point of a solute C. Nature of the solute. D. Number of solute particles in a solution
D
During an endothermic chemical reaction, what is the source of energy that causes the reaction to continue? A. Materials that are part of the system. B. Reactants involved in the reaction C. Chemical bonds of the reaction products D. Materials in the surroundings of the system
D
The fact that ice is less dense than water is related to the fact that___. A. Ice has a molecular structure in which water molecules are arranged randomly. B. The molecular structure of ice is much less orderly than that of water. C. The molecules of ice are held to each other by covalent bonding. D. Ice has a molecular structure that is an open framework held together by hydrogen bonds.
D
The solubility of potassium chloride is 34 g KCl/100 g H2O at 20 degrees Celsius. What is the maximum amount of KCl that can dissolve in 200 g of water at 20 degrees Celsius? A. 6800 g B. 17 g C. 34 g D. 68 g
D
What is the concentration of a solution? A. A measure of the volume of solvent used to make the solution. B. A measure of the number of moles of solute dissolved C. A measure of the amount of solute that can be dissolved D. A measure of the amount of solute in a specified quantity of solvent
D
What occurs in solvation? A. Solvent molecules bind covalently to solute molecules. B. Ionic compounds are formed. C. Solute ions separate from solvent molecules. D. Solvent molecules surround solute ions.
D
What type of compound is always an electrolyte? A. Polar covalent B. Non polar covalent C. Network solid D. Ionic
D
Which of the following are weak electrolytes in water? A. Polar compounds that ionize. B. Non polar compounds that do not ionize C. Ionic compounds that are soluble. D. Ionic compounds that partially dissociate in water.
D
Which of the following usually makes a substance dissolve faster in a solvent? A. Lowering the temp B. Decreasing the number of particles C. Increasing the particle size of the solute D. Agitating the solution
D
A crystal that absorbs water vapor from the air is__. A. Hygroscopic B. Aqueous C. Deliquescent D. Efflorescent
A
The bonds between adjacent water molecules are called___. A. Hydrogen bonds B. Polar covalent bonds C. No polar covalent bonds D. Ionic bonds
A
What causes Brownian motion in colloids? A. Collisions between particles of the dispersed phase and the dispersion medium. B. Variation in particle sizes within the colloid. C. Coagulation and settling of particles of the dispersed phase. D. Absorption of energy from light resulting from the dispersed phase.
A
Which of the following materials is a colloid? A. Smoke B. Bronze C. Vinegar D. Gasoline
A
Which of the following mixture types is characterized by the settling of particles? A. Suspension B. Colloid C. Solution D. Hydrate
A
Which of the following substances is less soluble in hot water than in cold water? A. CO2 B. NaNO3 C. KBr D. NaCl
A