Chemistry help please

Question

You have two beakers, one filled with 100-mL of sugar (mass= 180.0 g) and the other filled with 100-mL of water (mass= 100.0 g). You pour all the sugar and all the water together in a bigger beaker and stir until the sugar is dissolved.

a. Which of the following is true about the mass of the solution?

i. It's much greater than 280.0 g

ii. It's somewhat greater than 280.0 g

iii. It's exactly 280.0 g

iv. It's somewhat less than 280.0 g

v. It's much less than 280.0 g

PLEASE EXPLAIN WHY!!!

b. Which of the following is true about the volume of the solution?

i. It's much greater than 200.0 mL

ii. It's somewhat greater than 200.0 mL

iii. It's exactly 200.0 mL

iv. It's somewhat less than 200.0 mL

v. It's much less than 200.0 mL

PLEASE EXPLAIN WHY!!!

Answer 1

For a. , unless you spill some sugar or water, your mass should simply be the sum of the two ingredients you've added.  The mass of each of the constituents is unchanged.  In fact, you could separate the two by distillation, and have 180 g of sugar and 100 g of water all over again (assuming you had the right apparatus that would perfrom the distillation without any vapor loss).  So the answer is simply the sum of the masses of the added ingredients.

B. is a little trickier.  The sugar will all actually dissolve in the water.  Dissolved solids typically don't occupy as much space, so your volume is probably not the sum of the two volumes of the ingredients, but it is also not likely to decrease either, so I'd say the sugar would add a slight volume, while the water volume would be 200 mL