Answer:
b. The bromine (Br2) has reacted with the benzene, leaving fewer bromine molecules in solution.
Explanation:
Colour is caused by absorption of light of the frequency of “complementary colours”. Exactly which frequencies molecules absorb depends on the arrangement of electrons. Obviously, to break the Br-Br bond and the C=C bond in the reactants and replace them with two C-H bonds is a significant reordering of electrons and so the new molecule is no longer able to absorb the same frequencies as previously. Hence, a colour change, in this case from orange to colourless.
Answer:
An exothermic process releases heat, causing the temperature of the immediate surroundings to rise. An ethothermic process absorbs heat and cools the surroundings. Hope this helped.
Hg + O2 --> HgO + O
Note that Mercury has a variable valency.
Answer:
Option A=> -NHCOCH3 and option C = -CH3.
Explanation:
The option A that is -NHCOCH3 is CORRECT because it possesses lone pair of electron with the exception of group 7A elements. It is this lone pair that is used in the Activation of the ring towards substitution. Other groups that falls into this group are; OCH3, alkyls and many others.
Option B that is -COOH is good group for withdrawal of electron through Resonance. Other examples are NO2, -CN and SO3H.
Option C falls to the same category as option A above that is Activation of the ring towards substitution.
Option D falls to the same category as option B above that is group for withdrawal of electron through Resonance.
Answer: Combustion changes the potential chemical energy into kinetic energy in the form of heat. For combustion an organic wood combines with oxygen already in the air and undergoes a chemical reaction that gives off carbon dioxide,water,and energy in the form of heat and light.
