A.) Phosphate ion or Orthophosphate
d.) Hydroxide
D.) Ammonium
e.) Iron
C.) Nitrate
f.) Sulfur dioxide
Answer: Option (d) is the correct answer.
Explanation:
As it is known that like dissolves like. So, water being a polar compound is able to dissolve only polar compounds.
Hence, a compound that is ionic or polar in nature will readily dissolve in water. Whereas non-polar compounds will be insoluble in water.
As 
is a non-polar compound. Hence, it is insoluble in water.
On the other hand, 
is a polar compound due to difference in electronegativity of chlorine and carbon atom there will be development of partial charges. Hence, there will be dipole-dipole forces existing between them.
Whereas 
is an ionic compound and it will readily dissociate into ions when dissolved in water. Also, there will be ion-dipole interactions between sodium and nitrate ions.
Hence, will readily dissolve in water.
Thus, we can conclude that the compounds correctly arranged in order of increasing solubility in water are < < .
Answer:
2) Gas molecules do not have preferred direction of motion, their motion is completely random. 3) Gas molecules travels in straight line. 4) The time interval of collision between any two gas molecules is very small. 5) The collision between gas molecules and the walls of container is perfectly elastic.
