Answer:
The answer is 4.28 moles
Explanation:
This is super easy okay, you won't forget this!
Basically mole ratios, we're just looking at the coefficients in front of the compounds, multiplying them, and dividing them as we see fit.
In this example, you can see how you need 2 moles of lithium bromide (LiBr) for the reaction, and 2 moles of lithium chloride (LiCl) will be produced.
Basically, the <u>molar ratio</u> is when you divide numbers and see how much of this do I have for that (if that makes sense).
So if you were to divide the 2 moles of LiBr / 2 moles of LiCl = 1. So we know that the mole ratio for LiBr to LiCl is 1:1 or 2:2, either or, it's the same thing.
SO THE BIG IDEA, if we have 4.28 moles of lithium bromide reacting, we should also have 4.28 moles of lithium chloride produced, BECAUSE the <u>mole ratio</u> is 1:1.
I hope this makes sense please tell me if it doesn't, I will try my best to explain a little more.
Increased Evaporation/B is correct :p
Since this process involves a matter-state change from solid to liquid, melting is occurring.
Ionic compounds have very strong intermolecular 'bonds': this is because it is formed by a metal atom donating one or more electrons to a non-metal atom in order to result in complete valence shells, with the effect that opposite ions are formed (opposites attract). Hence a large input of energy is needed to overcome these 'bonds' and form a liquid from the giant solid ionic lattice - therefore ionic compounds have high melting and boiling points.
Conversely a covalent bond occurs between two non-metal atoms - unlike ionic compounds which form giant ionic structures, covalent bonds are used to form molecules. These only have weak intermolecular forces, which need a small energy input to overcome: therefore the melting and boiling points will be much lower.
Considering that the compound has been taken from the freezer, which is 0 degrees celcius or lower, the state change has occurred at a low temperature. This makes it extremely likely that the compound is covalent.
In conclusion, the correct answer is d.