A solid white substance A is heated strongly in the absence of air. It decomposes to form a new white substance B and a gas C. The gas has exactly the same properties as the product obtained when carbon is burned in an excess of oxygen. Based on these observations, can we determine whether solids A and B and the gas C are elements or compounds? Explain your conclusions for each substance.

Solid A and gas C are compounds but I don't know why. B doesn't have enough information... ??

5 answers

A breaks down to form two products; both a gas and a solid so it must be a compound. C is a gas the same as C + O2 ==> CO2; therefore, it is a compound. B may be a compound and it may be an element.
A is a element
B is a compound
C is a compound
ex. C + O2 = CO2
It's an element of compound
A is a hetrogenous
B is either an element or a compound