Asample of hydrated copper (ii) sulfate has a mass of 4.56 g. after heating, it has a mass of 2.92 g. what is the percent by mass of water in the hydrate?

36.0%.

Explanation:

The mass of water = mass of hydrated copper (II) sulfate - mass of copper (II) sulfate after heating = 4.56 g - 2.92 g = 1.64 g.

The percent by mass of water in the hydrate = (mass of water/mass of hydrated copper (II) sulfate)*100 = (1.64 g/4.56 g)*100 = 35.96% ≅ 36.0%.

for step 7 table c on the lab "newtons law of action"   the average time it took the car to travel .25 meters   was 1.92 seconds.

the average time it took the car to travel 0.50 meters was 2.61 seconds

hope this : )

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.