short questions?

Question

Which of these acid-base (neutralisation) reactions could be titrated using burette and flask to give a sharp end point?
A) sulphuric acid and alluminium oxide
B) sulphuric acid and magnesium hydroxide
C) sulphuric acid and magnesium oxide
D) sulphuric acid and sodium hydroxide

i know the answer is D, but i dont understand exactly why..and what is meant by shap end point?

2) Which compounds may result from mixing ethane and chlorine in the prescence of sunlight (the answer could be one of the below, two or even all)

A) CH3CH2Cl
B) CH3CH2CH2CH3
C) CH3CHClCHClCH3

I can understand how A and B are formed, but dont understand how C is formed.


3)Which compound has a boiling point which is influenced by hydrogen bonding? (only one answer)
A) CH3CHO
B) CH3OCH3
C) HCOOH
D) HCOOCH3

Arent all of them affected by hydrogen bonding?

Thanx for the help

Answer 1

the best titration occurs between strong acids and bases the moles used for acid equals to the moles present for base
so the best titration is between strong acid and strong base

a and c can be formed by chain reactions b does not include Cl

chain reactions caused by radicals which can be formed by sunlight too. and un selectively reacts with everyhing in the mediumn
3) try to write em in the drawing form
a ) H
/
CH3-C=O
no OH bond
b)

CH3 - O- CH3 bonds are between O and C
no OH bonds

c)
O
ıı
OH -C- CH3

OH hydrogen bond included

i am just quessing not really good at organics

but Hydrogen bond occurs between OH ON etc i can not remember all

that double bond O si on the C atom can not be written like that

Answer 2

1) Sodium hydroxide is monobasic: it has one reacting OH ion per mole. Magnesium compopunds are dibasic, with two OH- ions, and aluminum oxideforms a tribasic hydroxide. So you get a sequence of neutralizations with the first three, and it's hard to locate a "sharp" endpoint. Actually, H2SO4 is a poor acid to titrate with, because you have to titrate with the H2SO4 + OH- ===> HSO4- + H2O reaction, while avoiding or going for the HSO4- + OH- ===> SO4= + H2O reaction.

2) CH3CH2Cl is the product.

3) HCOOH is affested by hydrogen bonding, because it has an -OH group. A is an aldehyde, CH3CH=O, B is an ether, CH3-O-CH3, and D is an ester, CH3-O-HC=O. Hydrogen bonding is -O-H***O<