HSC Science (General) इयत्ता ११ वी - Maharashtra State Board Question Bank Solutions

Choose the correct option:

How many grams of oxygen will be required to react completely with 27 g of Al? (Atomic mass: Al = 27, O = 16)

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In CuSO₄.5H₂O the percentage of water is ______
(Cu = 63.5, S = 32, O = 16, H = 1)

Explain the term percentage composition.

Explain the term empirical formula.

Explain the term molecular formula.

Solve the following problem:

Work out the percentage composition of constituent elements in the following compound:

Lead phosphate [Pb₃(PO₄)₂]

(At. mass: Pb = 207; P = 31; O = 16; K = 39; Cr = 52; Na = 23; N = 14)

Solve the following problem:

Work out the percentage composition of constituent elements in the following compound:

Potassium dichromate (K₂Cr₂O₇)

(At. mass: Pb = 207; P = 31; O = 16; K = 39; Cr = 52; Na = 23; N = 14)

Solve the following problem:

Work out the percentage composition of constituent elements in the following compound:

Macrocosmic salt - Sodium ammonium hydrogen phosphate, tetrahydrate (NaNH₄HPO₄.4H₂O)

(At. mass: Pb = 207; P = 31; O = 16; K = 39; Cr = 52; Na = 23; N = 14)

Solve the following problem:

Find the percentage composition of constituent green vitriol crystals (FeSO₄.7H₂O). Also, find out the mass of iron and the water of crystallisation in 4.54 kg of the crystals. (At. mass : Fe = 56; S = 32; O = 16)

Solve the following problem:

The red colour of blood is due to a compound called “haemoglobin”. It contains 0.335% of iron. Four atoms of iron are present in one molecule of haemoglobin. What is its molecular weight? (At. mass: Fe = 55.84)

A substance, on analysis, gave the following percent composition: Na = 43.4%, C = 11.3% and O = 45.3%. Calculate the empirical formula. (At. mass Na = 23 u, C = 12 u, O = 16 u).

Solve the following problem:

Assuming the atomic weight of a metal M to be 56, find the empirical formula of its oxide containing 70.0% of M.

1.00 g of a hydrated salt contains 0.2014 g of iron, 0.1153 g of sulfur, 0.2301 g of oxygen, and 0.4532 g of water of crystallisation. Find the empirical formula. (At. wt.: Fe = 56; S = 32; O = 16)

Solve the following problem:

An organic compound containing oxygen, carbon, hydrogen, and nitrogen contains 20% carbon, 6.7% hydrogen, and 46.67% nitrogen. Its molecular mass was found to be 60. Find the molecular formula of the compound.

Solve the following problem:

A compound on analysis gave the following percentage composition by mass: H = 9.09; O = 36.36; C = 54.55. Mol mass of compound is 88 g mol⁻¹. Find its molecular formula.

Solve the following problem:

Carbohydrates are compounds containing only carbon, hydrogen, and oxygen. When heated in the absence of air, these compounds decompose to form carbon and water. If 310 g of a carbohydrate leaves a residue of 124 g of carbon on heating in absence of air, what is the empirical formula of the carbohydrate?

Write the drawbacks of Rutherford’s model of an atom.

Write the characteristics of adsorption.

Explain why a finely divided substance is more effective as adsorbent?

Mention factors affecting adsorption of a gas on solids.