1. What volume in mL of 28.0M H2SO4 is needed to contain 53.0g of H2SO4?

2. How many grams of calcium hydroxide Ca(OH)2 are needed to make 532.0 mL of a 1.90M solution?

3. If 12 mL of water are added to 124mL of a 0.505M K2SO4 solution, what will the molarity of the diluted solution be?

1. V=19.3 ml

2. mass=74.8g

3. molarity of dilted solution=0.463M

Explanation:

1.

First calculate the mole ,

given mass=53g

molecular weight=98g/mole

mole=0.54

molarity=28M

V=19.285ml

V=19.3 ml

2.

First calculate the mole of calcium hydroxide,

molariy=1.9M

volume=532 ml=0.532L

mole=1.01 mol;

molecular weight of calcium hydroxide= 74g/mol

mass=74.8g

3.

First calculate the mole before adding water

molariy=0.505M

initial volume=124 ml=0.124L

mole=0.063 mol;

after dilution volume=136 ml =0.136L

quantity of solute remains unchanged during dilution of solution.

molarity of dilted solution=0.463M

c is the answer because when something is left after something evaporates that shows the chemical change.

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.