Question

25.0 g sample of compound A is mixed with a 40.0 g sample of compound B. a chemical reaction occurs. Once the reaction is complete, the final mixture has a mass of 55.0g. What happens to the “missing” mass? How much mass is missing?

Answer 1

Answer:

Explanation:

Mass of compound A  = 25g

Mass of compound B = 40g

Mass of final mixture = 55g

What happens to the missing mass?

According to the law of conservation of mass, in chemical reaction, matter is transformed from one form to another but cannot be created nor destroyed.

We expect the final mass of the mixture and that of the reacting compounds to be the same but the opposite is the case.

There is a mass loss which typifies most chemical reaction.

The reason for this is that some of the masses must have been lost by the production of gaseous species which are unaccounted for.

The missing mass:

  Total mass expected  = mass of A + mass of B = 25 + 40 = 65g

Missing mass = expected mass - mass of final mixture = 65 - 55 = 10g