The element which can combine with oxygen to form an acid anhydride of the form XO2 2 is

The number of molecules of helium gas contained in 11.5g of the gas is

The constituent of petroleum fraction used in surfacing road is

When Calcium ethynide is decomposed by water, the gas produced is

In the extraction of Aluminium, the silica impurity is removed by

At a given temperature and pressure, a gas X diffuses twice as fast as gas Y. It follows that

Silver and Gold are metals found as free uncombined elements in the earth's crust, which makes them to be referred to as

The constituents of Alnico are Aluminium, Nickel and

During the fractional distillation of crude oil, the fraction that distills at 200 - 2500 0 C is