When two substances A and B are powered together in a pestle and mortar, a large amount of heat is envolved. As a result a new substance C is formed. What is the nature of the new substance ? a) Element
b) Mixture
c) Both a and b
d) Compound

Calcium carbonate decomposes at high temperatures to give calcium oxide and carbon dioxide as shown below. caco3(s) cao(s) + co2(g) the kp for this reaction is 1.16 at 800°c. a 5.00 l vessel containing 10.0 g of caco3(s) was evacuated to remove the air, sealed, and then heated to 800°c. ignoring the volume occupied by the solid, what will be the mass of the solid in the vessel once equilibrium is reached?