Understanding Solutions
Often called a universal solvent, this substance dissolves many other substances, and is often the largest component of solutions
Water
Describe one method for making a solution more concentrated
1. Adding solute
2. Removing solvent
The type of substances which will turn red litmus paper blue
The type of ion produced when bases are mixed with water
Hydroxide (OH-)
The type of ion produced when acids are mixed with water
Hydrogen Ion (H+)
The solute found in a solution of soda water
Carbon Dioxide (CO2)
The percent concentration of a solution of 20 grams of Hydrogen Peroxide in a 200 gram solution.
10% Hydrogen Peroxide Solution
The type of gas produces when acids react with metals:
Bonus: The type of gas produced when acids react with carbonates
Hydrogen gas (H2)
Bonus: Carbon Dioxide (CO2)
The range of pH values that indicate an acidic solution:
<7
0-7
Solution A has a pH of 1.6 and Solution B has a pH of 3.5. Which solution has a greater concentration of Hydrogen ions?
Solution A. The lower the pH, the greater the concentration of Hydrogen ions (H+) and the stronger the acid.
A mixture of small, undissolved particles that do not settle out and are too small to be seen without a microscope. They also scatter light.
Bonus: Give two examples of colloids
Colloid
Fog, Milk, Shaving Cream, Smoke
If you increase the temperature of a liquid solvent, the solubility of a dissolved gas will:
Bonus: What 3 factors can affect solubility?
Decrease
(Gas particles speed up when temperature increases, making it more likely that the particles will escape the solution, and harder to stay dissolved.)
Bonus: Pressure, the type of solvent, and temperature
Bases taste like this:
Bitter
The type of reaction between an acid and a base which produces H2O and some kind of salt:
Neutralization
The range of pH values that indicate a basic solution:
>7
7-14
The method by which the particles in a suspension can be separated
Filtration or Settling
Explain how you can tell if a solution has become saturated.
Bonus: How do you make a supersaturated solution?
Bonus: Heat the solution to increase the solubility, then slowly cool the solution. The solution will have more solute dissolved than it can normally contain.
Name 2 common uses for acids and 2 for bases
Acids: Foods (vinegar, fruits), Stomach acid
Bases: Cleaning products, baking soda, soap, antacids
Name two examples of strong acids, and one example of a weak acid.
Strong acids: Hydrochloric acid, Sulfuric acid, Nitric acid
Weak acids: Acetic acid, Citric acid
The salt that is produced from combining Hydrochloric Acid (HCl) and Potassium Hydroxide (KOH)
Potassium Chloride (KCl)
KOH + HCl --> H2O + KCl
Explain why de-icing solutions (ethylene glycol in water) are sometimes sprayed on airplanes before takeoff
Solutes lower the freezing point of a solution beyond that of the solvent alone. The lower freezing point prevents ice from forming on the plane during flight.
Explain why oil and water will not mix to form a solution.
Water is a polar molecule and oil is a non-polar molecule.
Ionic and Polar compounds will dissolve in polar solvents, and non-polar compounds will dissolve in non polar solvents.
Explain how acids can be used for testing the purity of a piece of gold jewelry
Pure gold will not corrode in acid. An object called a touchstone is used to test purity. The gold object is scraped on the touchstone and acid is poured on the streak. The more gas bubbles the streak produces, the lower the purity of gold. In this case it most likely contains a large amount of copper or zinc.
Explain what determines whether or not an acid or base can be considered a strong acid.
No, the pH may be close to 7 but it depends on the strength and amount of the acid and base solutions being combined.
Example: a small amount of weak acid mixed with a large amount of a strong base will only somewhat neutralize the solution, moving the pH slightly closer to neutral (7) but may still remain basic.