Answer:
Samples A and B are mixtures
Explanation:
For sample A, we were told that the initial density of the solution is 0.77/gmL. After distillation, the liquid left has a density of 1.04/gmL. Apparently, A is a mixture of liquids.
As for sample B, the spread of the chromatogram resulting in different colours show that the sample B is not pure. It is a mixture of substances. A pure sample will yield only a single spot.
Answer:
See image attached
Explanation:
a)
The full reaction mechanism of step 1 was obtained from Bartleby and attached to this answer. The steps involved in the reaction are:
1) Loss of Br- and formation of a carbocation
2) Attack of CH3CN on the carbocation
4) Formation of a quaternary nitrogen intermediate
5) Attack of water on the quaternary nitrogen intermediate
6) Loss of the water molecule
5) Formation of the amide product
b)
i) sodium hydroxide
ii) HCl
Light shining through the less dense material.
Answer:
At end point there will a transition from pink to colorless.
Explanation:
As the student put the vinegar in the titrator and NaOH in the beaker, it means that he has poured phenolphthalein in the NaOH solution.
The pH range of phenolphthalein is 8.3-10 (approx), it means it will show pink color in basic medium.
So on addition of phenolphthalein in NaOH the solution will become pink in color.
When we start pouring vinegar from titrator neutralization of NaOH will begin.
On complete neutralization , on addition of single drop of vinegar the solution will become acidic and there will be complete disappearance of pink color solution in the beaker.
