Types of Reactions
What are the two types of reactions that we discussed at the beginning of the chemistry unit?
Chemical and Physical Reactions
What does it mean when it appears that something has disappeared in water?
It dissolved
What causes powder #5 to turn into a liquid?
Heat
Which powder looks like little cubes?
Salt. Powder #2.
How can a magnifying glass or microscope be helpful in identifying powders?
You get a closer look
What type of reaction bubbles and releases a gas?
Is it possible to undo the process of dissolving? If so, how?
Evaporate the liquid.
The iodine test is best for which powder and what happens to the powder when iodine is added?
Powder 1: Cornstarch. It turns blue-black.
How many mixtures container sugar?
3 mixtures. Mixture 6, 8, and 10.
Why is color NOT a good way to identify the powders?
They are all just a different shade of the same color.
Is dissolving a physical or chemical reaction?
Physical
What is made when a solute and solvent is mixed together during the dissolving process?
Hint: You solve these in math class
When vinegar was added to powder #3, what happened?
It fizzed and bubbled.
Which mixtures contained three powders?
Mixture 9 and 10.
If some of the powder is accidentally spilled do I need to put it back in the container so it is not wasted? Why or why not?
No so the powders are not contaminated.
When something gets broken, is it a physical or chemical reaction?
Physical Reaction
They measure liquids.
When water was added to powder #4, what happened?
Which two powders had the same results when mixed in both water and vinegar?
Sugar and Salt. They both dissolved.
How many powder containers were supposed to be open at a time.
1 container at a time.
What is a big difference between a chemical and physical reaction?
A chemical reaction makes something new and physical reaction does not.
Name two things you should do in a science laboratory to keep yourself safe.
Don't run around, listen to directions, don't eat anything, wear goggles, etc.
What test helps you tell the difference between salt and sugar?
Microscope or Heat
When a powder turns blue-black from iodine it means it contains what?
It contains starch.
Magnifying glass and pipette.