PLease need help have 40min left!

Well its been a little more than an hour but i stumbled across your questions so i hope this is still useful.

The first question is a dimensional analysis problem. You multiply and cancel the units. You know how much volume of solution you have, and how many moles of sucrose are in a given volume of solution, so if you use both of those numbers you should be able to figure out the answer.  0.0553 L sucrose solution x 1.88 moles sucrose/L sucrose solution = 0.104 moles sucrose if you are rounding to three significant figures, which would be correct as three is the fewest given in the question. The liters of sucrose solution cancel leaving just moles of sucrose.

The second question requires you to use the formula for mass percent which is for your solution would be (mass of solute)/(total mass of solute and solvent)*100 = (144 g KCl / 144 g KCl + 450 g H2O)*100 = 24.2 % KCl by mass in aqueous solution. Feel free to check my arithmetic and rounding on your own calculator.

Good luck. Learning chemistry is tremendously rewarding once you get past some initial tedium, but if you think about each problem and what is actually happening carefully rather than searching for a pattern to copy you will find most of these types of problems are very simple. If your teacher has not properly explained dimensional analysis or anything else feel free to ask.