Ramesh took two beakers A and B containing hot water and cold water respectively . In each beaker he dropped a crystal of copper sulphate . He kept it undisturbed. After some time what did he observe ? Why ?
. A 15.0 mL sample of HNO3 of unknown concentration was titrated with 0.109 M NaOH. A volume of 18.6 mL of the base was needed to neutralize the acid sample. What is the molarity of the HNO3 solution?
2) Fill them with hot & cold water respectively.
To answer this question, we need to understand the solubility of copper sulphate in hot and cold water.
Copper sulphate (CuSO4) is a highly soluble compound. It dissolves easily in water due to the attractive forces between the copper ions (Cu2+) and sulphate ions (SO4^2-). However, the solubility of copper sulphate is temperature-dependent.
In hot water, the kinetic energy of water molecules is higher, leading to increased collisions and more effective breaking of the attractive forces between the copper and sulphate ions. This results in a higher solubility of copper sulphate in hot water.
On the other hand, in cold water, the kinetic energy is lower, leading to fewer collisions between water molecules and copper sulphate crystals. As a result, the solubility of copper sulphate in cold water is lower compared to hot water.
Now, let's consider Ramesh's experiment:
- When he dropped a crystal of copper sulphate in the hot water (beaker A), he observed that the crystal dissolved rapidly, dispersing throughout the water. This is because the high temperature of the water facilitated the dissolution of copper sulphate, allowing the crystal to break down and disperse evenly in the solution.
- In the cold water (beaker B), Ramesh observed that the crystal of copper sulphate did not dissolve or dissolve very slowly. This is because the lower temperature of the water hindered the dissolution process, resulting in the crystal remaining intact or dissolving at a much slower rate.
In summary, Ramesh observed that the crystal of copper sulphate dissolved quickly in hot water (beaker A) while it did not dissolve or dissolved slowly in cold water (beaker B). This difference in dissolution rate can be attributed to the temperature-dependent solubility of copper sulphate, where higher temperatures increase solubility and facilitate dissolution.