Q7: Yeah this one's a sneaker!

The rounding is justified here for very close answers because you round UP on the percentage and DOWN on the molar mass, and you're rounding by approximately the same magnitude, so the rounding "cancels itself out". Therefore, A is the correct answer.

Otherwise, I agree that rounding UP would require a correct later. But since we did both during the calculation, they do cancel out and no correction is needed later on.

If you check it with a calculator (just did), you'll see that 7.04 g is the actual answer.

Q38: It's a pretty specialized concept, which is why we didn't talk about it.

A coordinate bond is a covalent bond (sharing bond) where all of the electrons are supplied by only ONE of the atoms involved.

You'll come across this term in pretty COMPLEX molecules, such as... coordination complexes, which we see in this question.

So if you run across another COMPLEX molecule, chances are it's got coordinate bonds.