120 ml of sugar solution has a density of 1.22g/cm3. when an additional unknown amount of sugar was added to the solution, the volume of the solution was raised by 15ml and the density becomes 1.38g/cm3. how much sugar was added to the solution

You added 40 g sugar to the solution.

Step 1. Calculate the mass of the first solution.

Mass1 = 120 mL × (1.22 g/1 mL) = 146.4 g

Step 2. Calculate the mass of the second solution.

Volume 2 = 120 mL + 15 mL = 135 mL

Mass 2 = 135 mL × (1.38 g/1 mL) = 186.3 g

Step 3. Calculate the mass of the sugar.

Mass of sugar = mass2 – mass1 = 186.3 g – 146.4 g = 40 g

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.