Acids
BONUS 500 Points!
Name 3 properties of acids
Tastes sour
Preserves things
Contains H at the front
Reacts with metals and carbonates
Name 3 properties of bases.
Feel slippery
Contain a hydroxide group (OH)
Accept hydrogen atom
Two substances that are mixed but not chemically bonded.
What is the difference between solutes and solvents?
A solvent dissolves something else.
A solute gets dissolved.
What is a chemical equation?
A way to describe a chemical change using symbols instead of words.
On the pH scale, which numbers indicate that a substance is acidic?
0-6
What color would a pH test strip turn if dipped in an extremely basic substance?
Purple or dark blue
BONUS 500 points!
What is a heterogeneous mixture? Give an example.
A mixture that is not evenly distributed!
Example: vegetable soup
In air, what is the solvent and what is the solute?
Solvent: nitrogen
Solute: oxygen, carbon dioxide, other gases
Physical change! No new substance was created.
How do we define an acid?
A substance that donates a hydrogen atom
Give an example of a very basic liquid.
Cleaning products!
Is salt water an example of a homogeneous or heterogeneous mixture?
Homogeneous!
For vinegar, what is the solvent and what is the solute?
Solvent: water
Solute: acetic acid
BONUS 500 POINTS!
Describe the difference between a physical and a chemical change.
Physical change: The appearance changes but no bonds are broken.
Chemical change: Chemical bonds are broken and new molecules are formed!
What is a carbonate? Also give a substance that contains carbonate.
CO3
Limestone, chalk, eggshells
If a liquid has 5 hydrogen ions and 7 hydroxide ions, is it acidic or basic?
Basic!
Isopropyl alcohol and water are mixed together. Propose a method of separating these two liquids.
Distillation.
How do solutes affect the boiling point and freezing point of solvents?
Solutes lower the freezing point and raise the boiling point
What is the Law of Conservation of Mass?
In a chemical reaction, no mass is created or destroyed.
The total mass of the reactants will be equal to the total mass of the products.
How do acids preserve things? Give an example.
The acidic environment prevents bacteria from growing!
Normally, food spoils because of bacteria.
No bacteria? No decay!
Examples: pickles, bodies in bogs
If Ca(OH)2 were placed in water, what would happen?
Ca would dissociate from OH.
Name 4 methods of separation and give an example of each.
Filtration
Magnetism
Centrifugation: Spinning a mixture in a circular motion, causing heavier particles to settle to the bottom of the test tube.
Distillation: Exploiting the boiling points of two liquids, catching the vapor of one and condensing it into another beaker.
Evaporation: Causing one component to vaporize, and leaving behind the precipitate.
Why do you think people call water the "universal solvent"?
Water can dissolve the largest variety of substances
Balance the following equation:
CH4 + O2 --> CO2 + H2O
CH4 + 2O2 --> CO2 + 2H2O