Using the rules for significant figures, the correct answer for the expression $${{0.02858 \times 0.112} \over {0.5702}}$$ will be

Production of iron in blast furnace follows the following equation

Fe₃O₄(s) + 4CO(g) $$\to$$ 3Fe(l) + 4CO₂(g)

when 4.640 kg of Fe₃O₄ and 2.520 kg of CO are allowed to react then the amount of iron (in g) produced is :

[Given : Molar Atomic mass (g mol^$$-$$1) : Fe = 56, Molar Atomic mass (g mol^$$-$$1) : O = 16, Molar Atomic mass (g mol^$$-$$1) : C = 12]

Compound A contains 8.7% Hydrogen, 74% Carbon and 17.3% Nitrogen. The molecular formula of the compound is,

Given : Atomic masses of C, H and N are 12, 1 and 14 amu respectively.

The molar mass of the compound A is 162 g mol^$$-$$1.

A commercially sold conc. HCl is 35% HCl by mass. If the density of this commercial acid is 1.46 g/mL, the molarity of this solution is:

(Atomic mass : Cl = 35.5 amu, H = 1 amu)