15Magnified salt crystals. What are solutions?A homogeneous mixture
16solvent: the water alone solution: the salt and water together solute: the salt alonesolvent: the water alonesolution: the salt and water togetherCl-Cl-Na+Na+WaterWater
17http://www. chem. iastate Double click on this ↑ to see salt dissolving.
18solvent: the water alone solution: the salt and water together solute: the salt alonesolvent: the water alonesolution: the salt and water togetherCl-Cl-Na+Na+WaterWater
19Salt ions being separated by collisions of water molecules.
20suspension: the stuff that will not dissolve, but rather sinks or floats. Blood is partly a suspension.A glass of river wateris partly a suspension.
21What are some solubility tricks? Grind large pieces of solute into small pieces, thereby increasing surface area for the water molecules to collide into.Raise the temperature to increase collisions of H2O’s into solute.Stir or shake which increases the collisions.surface area: smaller particles have more surface area compared to one large particle.
22surface area: smaller particles have more surface area compared to one large particle.
23How much solute can dissolve in the solvent? It depends on the conditionsand the properties of the solution being made.
24What does supersaturated mean? There is so much solute,that there aren’t enoughwater moleculesto surround the solute.
25How does temperature affect solubility? Usually, the warmer, the better.
26But gases dissolve better at lower temperatures.
27How does pressure affect solubility How does pressure affect solubility? The more pressure (lid on) the better the dissolving of a gas in a liquid.Take this 12 question quiz over solubility. Allow pop-ups for answers to be given.
29Can electricity go through water? If it has salts…yes If it has sugars or proteins…no.conduction of electricity:what ions do in water
30Which has the greatest solubility? CaCO3 or FeS or HgCl2 or KClO4
31Which liquid makes the light shine brighter? A. A dilute solution of water and ammoniaB. A dilute solution of water and sulfuric acid
32The unique properties of water enable life to exist on Earth The unique properties of water enable life to exist on Earth. Which of these is a property of pure water?F Its solid form is more dense than its liquid.G It has a low heat absorption capacity.H It is slightly more acidic than air.J It dissolves many substances.
33According to the law of conservation of mass, how much zinc was present in the zinc carbonate?
34A. Shaking exposes the salts to the solvent more quickly. A student pours mineral salts into a bottle of cold water. Which of the following best explains why shaking the bottle will affect the dissolving rate of the salt?A. Shaking exposes the salts to the solvent more quickly.B. Shaking helps more water to evaporate.C. Shaking causes more ions to precipitate out of solution.D. Shaking equalizes the water temperature.Take this 25 question quiz to check your understanding of solubility.
35F gaseous solute in a gaseous solvent Soda water is a solution of carbon dioxide in water. This solution is composed of aF gaseous solute in a gaseous solventG liquid solute in a liquid solventH gaseous solute in a liquid solventJ liquid solute in a gaseous solventTake this 6 question quiz to check your understanding of solubility.
36Solid KNO3 was added to each beaker Solid KNO3 was added to each beaker. Each beaker was stirred at the same rate until all of the solid dissolved. The table shows the solubilities of KNO3 at different temperatures. How will the rates of dissolving compare?A. KNO3 will dissolve faster in Beaker B because of increased surface area.B. KNO3 will dissolve faster in Beaker A because the water molecules are farther apart.C. KNO3 will dissolve faster in Beaker B because the overall kinetic energy is increased.D. KNO3 will dissolve at the same rate in Beaker A and Beaker B because the concentrations are the same.
37A solution which has a concentration that exceeds its predicted solubility at a certain temperature and pressure would be:A unsaturated.B saturated.C supersaturated.D dilute
38What are acids?Water molecules exist in equilibrium with hydrogen ions and hydroxide ions.H2O ↔ H+ + OH-H+OH-
39What are acids?Water molecules exist in equilibrium with hydrogen ions and hydroxide ions.H2O ↔ H+ + OH-orH+OH-
40What are acids?Water molecules exist in equilibrium with hydrogen ions and hydroxide ions.H2O ↔ H+ + OH-Just a proton=H+OH-
41What are acids?Water molecules exist in equilibrium with hydrogen ions and hydroxide ions.H2O ↔ H+ + OH-Hydrogen ions wishthey had their electron back.They feel naked without an electron.H+OH-
42These are all acids because the hydrogens all transfer their electron to the other elements, then are left as a solitary proton that would like any electron from any element nearby.HClH2SO3HNO2H3PO2HNO4H2SO5HI
43Even though these compounds have hydrogens, none of them are acids because none of the hydrogens “transferred” the electron.They are all sharing electrons and therefore do not feel naked.
44Acid: naked hydrogen ions, pH of → 6.9Base: OH ions searching for another hydrogen,pH of → 14
47Concentrated acidcan be diluted by adding more water.
48What are buffers? Weak acids or bases that can react with strong acids or basesto prevent sharp, sudden changes in pH.
49pH indicators Litmus paper tells acid or base pH paper tells pH numbers
50Approximate the pH of the WaterApplesBeansMilkShrimp
51pH and its effect on reactions Take this 25 question quiz to check your understanding of pH.
52What is the difference between: strong acid and a weak acid? Double click this↓ to see hydrogens transferring.3 out of 3transferred1 out of 3transferred6 out of 6transferred2 out of 6transferred
53Water is the universal solvent because of its amazing properties which are mostly due to its polarity.
54The table below shows the pH values of samples of substances. According to the table, which of these substances is basic?A. rainwater.B. drain cleaner.C. distilled water.D. soda water.
55The water from hot springs near the Ebeko volcano in the Pacific Ocean has a very low pH. A low pH indicates which of the following about the water?A. It has no detectable H+ or OH- ions.B. It has equal concentrations of H+ and OH- ions.C. It has high concentrations of H+ ions.D. It has equal numbers of positive and negative ions.
56A student was assigned to take water samples from a lake near his home A student was assigned to take water samples from a lake near his home. He measured the pH of one of the water samples to be 6.0. Which of the following best describes this sample of water?A. highly acidicB. slightly acidicC. highly basicD. slightly basic
57A patient has chronic indigestion due to an overproduction of stomach acid. Which foods should the patient avoid until the condition is resolved?A. vegetables.B. citrus.C. dairy/egg.D. starches.
58The reaction catalyzed by the bacterial enzyme ß-galactosidase forms a dark-colored end-product when the cells are grown on a particular agar medium.As more product is formed, the cells become darker. Students performed an experiment to determine the optimum pH for activity of this enzyme.Their results are shown in the illustration of bacterial colonies.Based on these data, the students should conclude that ß-galactosidase functions best at which pH?A.5B.7C.9D.11
59If a lab group were using hydrochloric acid to perform a substitution reaction, which precaution would not be a concern?A FlammabilityB HealthC ReactivityD Contact