Which indicator would best distinguish between a solution with a ph of 3.5 and a solution with a ph of 5.5?
(1) bromthymol blue (3) litmus
(2) bromcresol green (4) thymol blue

The pH range of given indicators are

i) bromothymol blue : 6 (yellow) to  7.6 (blue) : so it cannot be used for the given condition

ii) litmus : it senses the change between acid and base. blue litmus turns red in acidic medium (from basic or neutral) however here both the solutions are acidic so we cannot use it

iii) bromocresol green : the pH range is 3.8-5.4. Below 3.8 it is yellow and above 5.4 it is blue

thus we can use it for two solutions as

a) in solution of pH = 3.5 it will show yellow colour

b) in solution of pH =5.5 it will show blue colour

hence answer is Bromocresol green

iv) thymol blue: pH rang is 6.0 - 7.6, so cannot be used

i'm pretty sure its b i might be wrong though!

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.