Of the following compounds, the most acidic is

When concentrated HNO₃ is heated with P₂O₅, it forms

Carbogen is 

In the alumino-thermite process, Al acts as 

For making good quality mirrors, plates of flint glass are used. These are obtained by floating molten glass over a liquid metal which does not solidify before glass. The metal used can be 

Nitrogen shows different oxidation states in the range

A hydride of nitrogen which is acidic is 

The mixture of conc.HCl and HNO₃ made 3:1 ratio contains 

Red lead is

In curing cement plasters water is sprinkled from time to time.This helps in