A) Why is calcium fluoride not used in toothpaste?
B) Why is calcium fluoride not used to fluoridate city water supplies?
C) Both A and B are good questions for the answer given.
D) Neither A nor B is a question that can be answered with the answer given.
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Multiple Choice
A) No, atoms forming chemical bonds are just the opposite. Chemical bonds forming or molecules reacting would be more analogous to strangers tending to stay together and friends dispersing.
B) Yes, atoms forming chemical bonds are analogous to friends in the rink. Atoms held together by covalent bonds represent a molecule.
C) No, opposites (like strangers) attract to form stable covalent bonds in the world of atoms and molecules.
D) Yes and No; No, because this behavior is not typical of atoms forming chemical bonds, but yes since it is typical of molecules interacting.
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Multiple Choice
A) 10.08 L
B) 10.00 L
C) 9.992 L
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Multiple Choice
A) Since concentration depends on how much mass is dissolved in a given volume, as the volume increases, the concentration decreases.
B) The concentration of a solution increases as the solute fits into the new spaces between the molecules.
C) Since it has a greater ability to dissolve more solute at a higher temperature, its concentration has decreased.
D) Since it has a greater ability to dissolve more solute at a higher temperature, its concentration has increased.
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Multiple Choice
A) Solubility depends on the solvent's ability to overcome the intermolecular forces in a solid.
B) Solubility depends on the solute's ability to overcome the intermolecular forces in the solvent.
C) Solubility is a measure of how strong a solvent's intermolecular forces are.
D) Solubility is a measure of how weak the intermolecular forces in the solute are.
E) none of the above
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Multiple Choice
A) The potassium used in the softener to replace the calcium and magnesium ions increases the sodium retention in the body.
B) Water softeners work by replacing the calcium and magnesium ions of the water with sodium ions; softened water contains increased levels of sodium ions.
C) The softened water leaches sodium from the body, so a person might not be getting the dietary recommended levels of sodium.
D) A person needs a certain level of calcium and magnesium in the water to help excrete the sodium from their body.
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Multiple Choice
A) agricultural runoff
B) sea water
C) brackish water
D) All of the above are the same.
E) None of the above can be purified by reverse osmosis.
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Multiple Choice
A) CH3OH
B) CH3SH
C) CH4
D) H-C
C-H
E) A, B and C
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Multiple Choice
A) The water molecule aligns such that the oxygen interacts with the sodium.
B) The water molecule aligns such that the hydrogens interact with the sodium.
C) The polarity of the water molecule is altered making the oxygen more positively charged.
D) The polarity of the water molecule is altered making the hydrogens more negatively charged.
E) none of the above
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Multiple Choice
A) dipole-dipole
B) induced dipole-induced dipole
C) dipole-induced dipole
D) ion-dipole
E) hydrogen bonding
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Multiple Choice
A) hydrogen bonding
B) induced dipole-induced dipole
C) covalent bonding
D) ion-dipole
E) polar-induced polar
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Multiple Choice
A) It is what you are doing now to answer this question.
B) It is the amount of solute in a given amount of solution.
C) It is the amount of solvent in a given amount of solution.
D) It is the given amount of solution in a given container.
E) It is the given amount of solvent per amount of solute.
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Multiple Choice
A) one liter of water with 1 gram of sugar
B) one liter of water with 2 grams of sugar
C) one liter of water with 5 grams of sugar
D) one liter of water with 10 grams of sugar
E) They all have the same volume.
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Multiple Choice
A) Sinks; The combined density of the plastic bottle plus the fresh water inside is greater than the density of the ocean water.
B) Floats; The bottle filled with fresh water floats in ocean water because it is less dense than the ocean water.
C) Floats then sinks; The bottle filled with fresh water floats in ocean water until the fresh water reaches the same temperature as the ocean water, at which point it sinks.
D) Sinks slightly; The added density of the plastic bottle will cause the bottle to sink slightly. It would most likely sink less than a foot where the density of the ocean water would be equal to or greater than the bottle of fresh water.
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Multiple Choice
A) a mole of gold
B) a mole of helium
C) a mole of lead
D) All of the above have the same number of atoms.
E) none of the above
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Multiple Choice
A) They have a polar ionic end and a long nonpolar tail.
B) Both dissolve oils.
C) Both are synthetic.
D) Both are biodegradable.
E) Both are made from fatty acids.
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Multiple Choice
A) 22 g
B) 100 g
C) 78 g
D) 1 L
E) 78g/L
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Multiple Choice
A) the molecule on the far left because the O-H bond is polar and the carbon and hydrogen bonds are nonpolar
B) the molecule in the middle because when the salts mix into the water, it will help separate the water and decrease the attraction for itself
C) The molecule on the right will form attractions with the polar ends of the water, allowing the gasoline a chance to mix with the water.
D) All of these molecules would be equally effective at increasing the mixing of gasoline and water.
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Multiple Choice
A) The more concentrated solution absorbs water from the less concentrated solution.
B) The less concentrated solution absorbs water from the more concentrated solution.
C) The less concentrated solution gets more dilute.
D) The ions migrate from the more concentrated solution to the less concentrated.
E) none of the above
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Multiple Choice
A) As temperature goes up, the solubility goes up.
B) As temperature goes down, the solubility goes down.
C) As temperature goes up, the solubility stays the same.
D) As temperature goes down, the solubility goes up.
E) both A and B
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