Mixtures
What is a mixture?
A combination of 2 or more substances
What is a solution?
When something dissolves into something else
A chemical reaction is reversible or irreversible?
Irreversible
What is the difference between a chemical and a physical change?
A chemical change
Example: Pepper and chalk
What is the best way to separate a mixture of cars and legos?
By hand sorting them
What is an example of a solution?
Does a new substance need to be formed in order for a chemical reaction to have occurred?
Yes, a chemical reaction has occurred if there is a new substance formed when 2 substances are mixed together
Physical
When salt mixes into water it is...
dissolving
What is an example of a mixture?
Example: trail mix
Solute
Name one way that burning wood provides evidence of a chemical reaction
example: odour, energy change (light and heat released)
A fire burning wood is what kind of change?
Chemical
On the pH scale, lemon juice is a(n)...
acid
What is the best way to separate rocks and sand? Why?
Sieving because the objects are different sizes and can be sorted through the sieve. The smaller parts will fall through and the larger parts will remain in the sieve.
Name 2 substances that are soluble in water
Example: sugar and salt
Name 2 ways to tell if a chemical reaction has occured
Examples: smell, energy change, gas bubbles, precipitate formation, color change
What is an example of a physical change?
Examples: glass breaking, can being crushed, mixing sand and water
On the pH scale, bleach is a(n)...
Base
Name 3 different separation techniques and explain how they work
Examples could include- hand sorting, sieving, distillation, filtering, evaporation, decanting
When we put sugar in our coffee, we are adding a _______ to a ___________.
solute to a solvent
What is carbon dioxide and how can it be produced?
Carbon dioxide is a gas that can be produced through chemical reactions such as mixing baking soda and vinegar.
What is an example of a chemical change?
Example: Batter turning into cake, food digesting in your body, a knife that is rusting
What is surface tension?
The tension of the surface film of a liquid caused by the attraction of particles in the surface layer. This allows insects to walk on water.