Question

Which of the following takes place during a decomposition reaction?
A. a complex substance breaks down into two or more simple substances
B. a single substance replaces another substance in a compound
C. two simple substances combine to form a new complex substance
D. parts of compounds switch places to form two new compounds

Answer 1

A

Answer 2

A

Answer 3

A. a complex substance breaks down to give two or more products

Answer 4

It's A. The reason is that decomposition, by definition, is when something complex breaks down. And if something breaks down, you MUST have two or more pieces. A random example would be H20. H2O will break down into H2 and O. Oxygen has a habit of bonding to other oxygens, so technically H2O will decompose into H2 and O2.

Answer 5

B is a common theme in chemistry. Something like AgCl and NaCO3 will swap out to create AgCO3 and NaCl (I can't remember my charges, so my subscripts are wrong). I can't remember the name of this.

C is simple compound creation/synthesis. This is like taking H2 and O2 and creating H2O (a more complex molecule with fewer 'pieces').

As for D, I dunno, I'm afraid. :/

Answer 6

@uber
your explanation for B. is wrong........
B. is the description of a Single Displacement reaction... and you hv given example of Double displacement reaction (which actually fits D. !!)

B. a single substance replaces another substance in a compound --- this is a Single Displacement reaction as in Fe + CuSO4 -----> FeSO4 + Cu

D. parts of compounds switch places to form two new compounds - this is a Double Displacement Reaction as in BaCl2 + Na2SO4 -------> BaSO4 + 2NaCl

Answer 7

le gasp! Thanks for catching that!