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1mol of CH₄ contains?

A. 6.02 × 1023 atoms of H B. 4g atom of hydrogen C. 1.81 × 1023 molecules of CH4 D. 3.0g of carbon Solution: (B) 1 mole of... View Article

A molar solution is one that contains one mole of solute in:

A. 100 ml of solvent B. 1000 g of solvent C. 1 liter solution D. 22.4 liter of solution Solution: (C) By definition, one molar solution... View Article

Crystals of which pair are isomorphous?

A. ZnSO4, SnSO4 B. MgSO4, CaSO4 C. ZnSO4, MgSO4 D. PbSO4, NiSO4 Solution: (A) ZnSO4 crystal is Orthorhombic SnSO4 crystal is... View Article

In known elements, the maximum number is of;

A. Metals B. Non-metals C. Metalloids D. None of these Solution: (A) If we look at the mordern periodic table, there are about a total... View Article

Number of molecules in 100 ml of each of O₂ NH₃ and CO₂ at STP are in the order:

A. CO2 > O2 > NH3 B. NH3 > O2 > CO2 C. All are equal D. NH3 = CO2 > O2 Solution: (C) As per Avogadro's law, if the... View Article

What will the atomic weight of metal be? Given, the vapour density of a metal chloride is 6.6 and its oxide contains 53% metal.

A. 21 B. 54 C. 27.06 D. 2.086 Solution: (C) VD of metal chloride = 66 To find, the atomic mass of metal. Let the weight of metal... View Article

If 10²¹ molecules are removed from 200 mg of CO₂, the number of moles of CO₂ left is:

A. 2.88 × 10−3 B. 28.8 × 10−3 C. 0.288 × 10−3 D. 1.66 × 10−3 Solution: (A) Molar mass... View Article

Which out of the following is not a homogeneous mixture?

A. Smoke B. Air C. Brass D. Aqueous solution of sugar Solution: (A) If we recall the definition of homogeneous solutions, these are... View Article

Calculate the number of moles in 1m³ gas at STP.

A. 4.46 B. 44.6 C. 446 D. 4460 Solution: (B) 1m3 = 1000 L At STP volume of 1 mol = 22.7 L Therefore, n (no. of moles) in 1m3 = 1000... View Article

An organic compound made of C, H and N contains 20% nitrogen. Its molecular weight is:

A. 70 B. 140 C. 100 D. 65 Solution: (A) The atomic mass of nitrogen = 14 Since the compound contains C, H and N, at least one N atom... View Article

In an experiment, 4 gm of M₂Ox oxide was reduced to 2.8 gm of the metal. If the atomic mass of the metal is 56 gm/mol, the number of oxygen atoms in the oxide is:

A. 1 B. 2 C. 3 D. 4 Solution: (C) 1 Mol M2Ox = (2 x 56 + 16 x) gm Now we consider, (2 x 56 + 16 x) of oxide = 112 gm metal... View Article

If the components of air are N₂ 78%, O₂ 21%; Ar 0.9% and CO₂ 0.1% by volume, what will be the molecular weight of air?

A. 28.9 B. 32.4 C. 16.4 D. 14.5 Solution: (A) Avg molar mass of air = (28×78+32×21+40×0.9+44×0.1) / 100 = 28.93... View Article

An organic compound containing C, H and N gave the following analysis: C = 40%; H = 13.33%; N = 46.67%. Its empirical formula would be;

A. C2H2N B. C3H7N C. CH4N D. CHN Solution: (C) Element % by mass Atomic mass Relative number of... View Article

A compound contains two oxygen atoms, four carbon atoms and the number of hydrogen atoms is double of carbon atoms. What is the density of vapour of this compound?

A. 88 B. 44 C. 132 D. 72 Solution: (B) M.F. C4H8O2 The compound contains two oxygen atoms, four carbon atoms and eight hydrogen... View Article

Calculate the amount of NaOH required to neutralize 100 mL 0.1 M H₂SO₄.

A. 40 g B. 0.4 g C. 80 g D. 0.8 g Solution: (D) 0.1 M H2SO4 = 1000 mL solution contains 0.1 mol H2SO4 100 0.01 mL solution contains... View Article

How much calcium oxide (CaO) can be obtained by heating 200 Kg of limestone that is 95% pure CaCO₃?

A. 104.4 kg B. 105.4 kg C. 212.8 kg D. 106.4 kg Solution: (D) Considering 100 kg impure sample has pure CaCO3 = 95 kg Therefore, 200... View Article

Percentage of Se in peroxidase anhydrous enzyme is 0.5% by weight (at. wt. = 78.4) then minimum molecular weight of peroxidase anhydrous enzyme is:

A. 1.568 x 104 B. 1.568 x 103 C. 15.68 D. 2.136 x 104 Solution: (A) In peroxidase anhydrous enzyme 0.5% Se is present means 0.5 g Se is... View Article