<span>In the reverse reaction HF is a reactant.</span>
Solids: have fixed shape and fixed volume
Liquids: have fixed volume
Gases: have neither fixed volume or fixed shape
This tells you that having a fixed shape is the most responsible characteristic of a solid's structure.
There are multiple answers to this question depending on what answer it's looking for. This is one of the right answers but I don't know if it's the one the question is looking for.
Answer: 1.80g
Explanation:
Molar Mass of AlCl3 = 27 + (3x35.5)
= 27 + 106.5 = 133.5g/mol
Number of mole of AlCl3 = 0.0135mol
Mass = 0.0135 x 133.5= 1.80g
Sorry this will probably be pretty long.
So think of the "control" as being something you yourself add to increase or decrease the effects in an experiment.
I'll give you an example so it is not as confusing.
Say you have decided to make an experiment on plants. Which plant can grow the fastest on which type of liquid? What is being added to this experiment? The liquid! Or all of the liquids you used. Like if you used Coke, Lime Gatorade, Orange Gatorade, and Water. Each drink will EFFECT each plant differently.
Hope I was of any hope?