Science (English Medium) इयत्ता १२ - CBSE Question Bank Solutions

Write the name of monomers used for getting the following polymers : Bakelite

Write the names of monomers used for getting the following polymer:

Teflon

Solid A is a very hard electrical insulator in solid as well as in molten state and melts at extremely high temperature. What type of solid is it?

Ionic solids conduct electricity in molten state but not in solid state. Explain

What type of solids are electrical conductors, malleable and ductile?

Explain the basis of similarities between metallic and ionic crystals.

Explain ionic solids are hard and brittle.

Copper crystallises into a fcc lattice with edge length 3.61 × 10⁻⁸ cm. Show that the calculated density is in agreement with its measured value of 8.92 g cm⁻³.

Calculate the mass percentage of benzene (C₆H₆) and carbon tetrachloride (CCl₄) if 22 g of benzene is dissolved in 122 g of carbon tetrachloride.

Calculate the mole fraction of benzene in solution containing 30% by mass in carbon tetrachloride.

Calculate the molarity of the following solution: 

30 g of \[\ce{Co(NO3)2 * 6H2O}\] in 4.3 L of solution.

Calculate the mass of urea (NH₂CONH₂) required in making 2.5 kg of 0.25 molal aqueous solution.

Calculate (a) molality (b) molarity and (c) mole fraction of KI if the density of 20% (mass/mass) aqueous KI is 1.202 g mL⁻¹.

Define Mole fraction.

Define Molality.

Define Molarity (M).

Define Mass percentage.

Concentrated nitric acid used in laboratory work is 68% nitric acid by mass in aqueous solution. What should be the molarity of such a sample of the acid if the density of the solution is 1.504 g mL⁻¹?

A solution of glucose in water is labelled as 10% w/w, what would be the molality and mole fraction of each component in the solution? If the density of solution is 1.2 g mL⁻¹, then what shall be the molarity of the solution?

How many mL of 0.1 M HCl are required to react completely with 1 g mixture of Na₂CO₃ and NaHCO₃ containing equimolar amounts of both?