How many molecules of oxygen are produced when a sample of 38.9 g of water is decomposed by electricity? A) 6.5 x 10^23
B) 1.3 x 10^24
C) 2.6 x 10^24
D) 2.3 x 10^25

A)

Explanation:

m = Mass of water = 38.9

M = Molar mass of water = 18 g/mol

= Avogadro's number =

The reaction of electrolysis would be

Number of moles of

From the reaction it can be seen that 2 moles of gives 1 mole of

So, number of moles of produced is

Number of molecules

So, of oxygen is produced.

the answer is c. nacl

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.