Answer : The mass in grams of calcium sulfate is 0.16 grams.
Explanation :
Molarity : It is defined as the number of moles of solute present in one litre of solution.
Formula used :

Solute is, 
Given:
Molarity of
= 0.0025 mol/L
Molar mass of
= 136 g/mole
Volume of solution = 485 mL
Now put all the given values in the above formula, we get:


Thus, the mass in grams of calcium sulfate is 0.16 grams.
Answer:
The yeast respired aerobically
Explanation:
The expectation here was that the yeast was going to put the sugar in the grape juice through fermentation, which is an anaerobic process that results in alcohol as one of the products. However since no alcohol was found in this particular example, it is fair to assume that maybe there was oxygen in teh muxture and therefore the yeast respired aerobically, producing water and carbon dioxide as products.