Why sodium sulphate is soluble in water whereas barium sulphate is sparingly soluble?
Barium sulphate is sparingly soluble in water because its hydration energy is lesser than the lattice energy and thus ions are not separated from each other. On the contrary in sodium sulphate the hydration energy is more than its lattice energy. Thus ions are separated from each other and pass in solution state.
Why polishing a surface beyond a certain limit may increase friction?
The area at each point of contact becomes very small when the surfaces are polished beyond a certain limit.However, the total area of the two surfaces in contact is very large. It is because, the number of points of contact becomes very large on making the surface highly polished. Since number of atoms (or molecules) of the two surfaces in contact is proportional to their area in contact, the force of friction increases due to greater force of molecular attraction between the two surfaces.
What is the difference between Liquidity ratios and Solvency ratios and what is the reason that a investor should consider these ratios before investing in any company
Liquidity ratios measure the short - term ability of a company to pay its maturing obligations to meet unexpected needs for cash whereas Solvency ratios measure the ability of the company to survive over a long period of time. Being a investor a person must consider these ratios because these ratios give a track to an investor how a company is working and how its performance certainly be in future. There are many types of Liquidity and Solvency ratios which tells different aspect about a company's performance.