HSC Science (Electronics) 11th Standard - Maharashtra State Board Question Bank Solutions

24 g of carbon reacts with some oxygen to make 88 grams of carbon dioxide. Find out how much oxygen must have been used.

Solve problem:

Calculate the number of atoms of the following. (Average atomic mass : N = 14 u, S = 32 u)

0.4 mole of nitrogen

Solve problem:

Calculate the number of atoms of the following. (Average atomic mass : N = 14 u, S = 32 u)

1.6 g of sulfur

Solve problem:

Calculate the number of moles of magnesium oxide, MgO in

1. 80 g, and
2. 10 g of the compound.

(Average atomic masses of Mg = 24 and O = 16)

Calculate the number of atoms of hydrogen present in 5.6 g of urea, \[\ce{(NH2)2CO}\]. Also calculate the number of atoms of N, C, and O.

Solve problem:

Calculate the mass of sulfur dioxide produced by burning 16 g of sulfur in excess of oxygen in the contact process. (Average atomic mass : S = 32 u, O = 16 u)

Explain the need of the term average atomic mass.

Explain formula mass with an example.

What is a limiting reagent? Explain.

Explain the term molarity

Write postulates of Bohr’s Theory of hydrogen atom.

Mention demerits of Bohr’s Atomic model.

Which properties of solvents are useful for solvent extraction?

Why should spotting of mixture be done above the level of mobile phase?

Define the Saturated solution.

Define Solvent extraction

List the properties of solvents which make them suitable for crystallization.

Select and write the most appropriate alternatives from the given choices.

Valence Shell Electron Pair repulsion (VSEPR) theory is used to predict which of the following:

Give four uses of adsorption.

Explain with example α - decay.