F.Sc Chemistry

27 g of Al= 1 mole of Al Balance this equation 4Al + 3O2 → 2Al2O3 Mole ratio Al : O2 4 : 3 1 : 3/4 Mass of O2 = 3/4 × 32 = 24g  Read More →

KMnO4 is such a substance which does not sublime.  Read More →

Moles of oxygen = 8/16 = 0.5 For two moles of oxygen, CO2 = 1 mole For one mole of oxygen, CO2 = 1/2 mole For 0.5 moles of oxygen, CO2 = 1/2 × 0.5 = 0.25 moles  Read More →

Since one mole of SO2 contain = 32 + 32 = 64g. One mole of SO2 gives two moles of oxygen and one mole of sulphur. Number of oxygen atoms = 2 × 6.022 × 1023 mole−1 Number of Sulphur atoms = 6.022 × 1023 mole−1  Read More →

Get the moles of nitrogen and use the idea of molar volume Mass of N2 = 1.4 g Moles of N2 = 1.4g / 28g per mole = 0.05 moles One mole of N2 at S.T.P has volume = 22.414 dm3 0.05 moles of N2 at S.T.P has volume = 22.414 × 0.05 = 1.12 dm3  Read More →

Water has highest percentage of oxygen because one atom of oxygen is bonded with two lightest atoms of hydrogen. % age of oxygen in water = 16/18 × 100 = 88.88  Read More →

Percentage of an element in a compound is obtained by dividing the mass of the element with the molar mass and multiplying with hundred. % age of nitrogen in NH3 = 14 / 17 × 100  Read More →

In combustion analysis of an organic compound, CO2 is absorbed in 50% KOH. It gives 2KOH + CO2 → K2CO3 + H2O  Read More →

Combustion analysis is performed for the determination of empirical of a compound, containing C, H2 and O2.  Read More →

In combustion analysis, carbon and hydrogen are converted into CO2 and H2O which are estimated by calculations. Anyhow, O2 is estimated by the method of difference. The %age of C and H2 are subtracted from 100 to get % of O.  Read More →