Answer:
A. C(s) + O2(g) → CO2(g) + 393.5 kJ
Explanation:
The formation of carbon IV oxide (CO2) is an exothermic process. n exothermic process is a chemical process in which heat is evolved. Speaking in lay man's terminology, heat is one of the 'products' of the reaction. This implies that heat is evolved by the process.
The formation of CO2 is always a combustion reaction where heat is evolved or released by the reaction system. Hence the reaction could be shown as;
C(s) + O2(g) → CO2(g) + 393.5 kJ
This implies that 393.5 kJ of energy is released in the reaction in the form of heat. Hence the answer given in the answer box.
Silver and lead are special elements, where silver is insoluble in all halogen anions (like AgCl, AgI, AgBr)
and lead is insoluble in sulphates and halogen anions ( PbSO4, PbCl2, etc.)
Mercury is special because it is the only metal that is a liquid at room temperature
hope this helps!!
Chemical test to distinguish between propane and propene. (i) Bromine water test : Propane contains double bond, therefore when we pour the bromine water to propene sample, it decolouries the bromine water whereas propane which is a saturated hydrocarbon does not decolourise the bromine water.
