Answer: b. 
is positive and 
is positive.
Explanation:-
As the temperature of the pack drops, the energy has been absorbed from the pack for dissolution of 
in water. Thus as the energy has been absorbed in the reaction, the reaction is endothermic and the change in enthalpy i.e. is positive.
The entropy is the measure of degree of randomness. The entropy increases when the randomness increases and the entropy decreases when the randomness decreases. When a substance dissolves in water, it dissociate into ions and hence the randomness increases thus the change in entropy i.e. is positive.
Coffee keeps you awake due to the caffeine in it. Caffeine is considered a psychoactive drug which energizes people by releasing a chemical in the body.
Answer:
depends on how many you have...
Explanation:
1) is called 3-methyl hexane because we choose the longest possible continuous chain which has 6 carbons and start numbering from the side that gives the branch lowest possible number.
2) is called 2-methyl-2-butene because we have to give the double bond lowest possible number but in this case double bond in position 2 from both sides so we start from the side gives the branch number 2 not 3
3) is called 7-Ethyl-4-decyne because we have to start from the side that gives the triple bond lowest possible number which is 4 and the branch will be at position 7 (note that the name of 10 carbon is incorrectly written in the choices is called decane (as alkane) or decyne when contains triple bond)
4) is called 2,3-Dimethyl pentane because it is 5 carbons (pentane) and we have two branches of the same alkyl (dimethyl) in positions 2 and 3
5) is called 1-Butanol because it contains 4 carbons and has one OH as functional group which take the suffix -ol in position 1 so we said the name as 1-butanol (remember to give the functional group lowest possible number)
6) is called propyl butyl ether because the longest chain is 4 carbons which called butyl and the smallest chain is propyl, it also has another name 1-Propoxy butane <span />
I believe the answer is A. However, I would double check the formula.
