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NCERT Solutions for Class 12 Chemistry Chemistry I Chapter 2 Solutions

NCERT Solution For Class 12 Chemistry Chemistry I

Solutions Here is the CBSE Chemistry Chapter 2 for Class 12 students. Summary and detailed explanation of the lesson, including the definitions of difficult words. All of the exercises and questions and answers from the lesson's back end have been completed. NCERT Solutions for Class 12 Chemistry Solutions Chapter 2 NCERT Solutions for Class 12 Chemistry Solutions Chapter 2 The following is a summary in Hindi and English for the academic year 2024-25. You can save these solutions to your computer or use the Class 12 Chemistry.

Question 1

NCERT Solutions for Class 12 Chemistry Chemistry I Chapter 2 Solutions

NCERT Solution For Class 12 Chemistry Chemistry I

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 each of the following solution (a) 30 g of Co(NO3)2.6H2O in 4.3 L solution (b) 30 mL of 0.5 MH2SO4 diluted to 500 mL.

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

H2S, a toxic gas with rotten egg like smell, is used for the qualitative analysis. If the solubility of H2S in water at S.T.P. is 0.195 m, calculate Henry's law constant.

Henry’s law constant for CO2 in water is 1.67 x 108 Pa at 298 K. Calculate the quantity of CO2 in 500 mL of soda water when packed under 2.5 atm CO2 pressure at 298 K.

The vapour pressure of pure liquids A and B are 450 and 700 mm Hg at 350 K respectively. Find out the composition of the liquid mixture if total vapour pressure is 600 mm Hg. Also find the composition of the vapour phase.

Vapour pressure of pure water at 298 K is 23.8 mm. 50 g of urea (NH2CONH2) is dissolved in 850 g of water. Calculate the vapour pressure of water for this solution and its relative lowering.

Boiling point of water at 750 mm Hg 99.630C. How much sucrose is to be added to 500g of water such that it boils at 1000C.

Calculate the mass of ascorbic acid (Vitamin C, C6H8O6) to be dissolved in 75 g of acetic acid to lower its melting point by 1.5 0C. Kf= 3.9 k kg mol–1.

Calculate the osmotic pressure in pascals exerted by a solution prepared by dissolving 1.0 g of polymer of molar mass 185,000 in 450 mL at 370C.

Suppose a solid solution is formed between two substances, one whose particles are very large and the other whose particles are very small. What kind of solid solution is this likely to be?

Amongst the following compunds identify which are insoluble, partially soluble and highly soluble in water?(i) phenol (ii) toluene (iii) formic acid (iv) ethylene glycol (v) chloroform, (vi) pentanol.

Two liquids A and B boils at 1450C and 1900C respectively. Which of them has a higher vapour pressure at 800C ?

Define ‘mole fraction’ of a substance in a solution.

What is expected value of Van’t Hoff factor for K3 [Fe(CN)6] in dilute solution?

State the formula relating pressure of a gas with its mole fraction in a liquid solution in contact with it.

What would be the value of Van’t Hoff factor for a dilute solution of K2SO4 in water?

In the determination of molar mass of A+B– using a colligative property, what may be the value of Van’t Hoff factor if the solute is 50% dissociated?

Why is the elivation in boiling point of water different in the following solution?(i) 0.1 molar NaCl solution.(ii) 0.1 molar sugar solution.

Why does the molality of solution remains unchanged with rise in temperature?

10 mL of liquid A was mixed with 10 mL of liquid B. The volume of the resulting solution was found to be 19.9 mL. What do you conclude?

Define Henry's law about solubility of a gas in a liquid.

A and B liquids on mixing produced a warm solution. Which type of deviation is there and why?

Why does sugar dissolve in water?

Why sugar does not dissolve in Benzene?

What temperature change is expected during the mixing of two liquids whose solution shows a negative deviation from Raoult’s law?

When is value of Van’t Hoff factor more than one?

Why does the boiling point of a solution exhibit negative deviation from the ideal behaviour?

What is Van’t Hoff factor i of the compound AlCl3?

Define Van’t Hoff factor ‘i’?

Define an ideal solution.

Differentiate between molarity and Molality?

What is the Van’t Hoff factor of a compound which undergoes tetramerisation in an organic solvent?

State Raoult’s law for dilute solutions?

Define Molality in terms of elevation in boiling point?

What are azetropes? Give an example.

What is the sum of the mole fraction of all the components in a three component system?

What is meant by vapour pressure? What is effect of temperature on it?

What do you understand by ‘colligative’ property?

Why is vapour pressure of solution of glucose in water is lower than that of water?

Draw the vapour pressure versus compositon diagram for an idal solution.

What are isotonic solutions? How do they differ from hypotonic and Hypertonic solutions?

What is the relationship between the eubllioscopic constant and the elevation in boiling point of the solution?

How is the alcohol and water are miscible in all proportions?

Why do gases nearly always tend to be less soluble in liquids as the temperature is raised?

How is osmotic pressure related to the concentration (or number of moles) of a solute in solution?

What is the effect of temperature on solubility of salt in water?

What happens to vapour pressure of solution if table sugar or table salt is added to water?

Define Raoult’s law?

Why is the osmotic pressure measurement preferred for determining molecular mass of proteins?

Why does the boiling point of a solvent increase by the presence of a solute in it?

A deci-molar solution of K4 [Fe(CN)6] is 50% dissociated at 300 K. Calculate the osmotic pressure of solution (R = 0.082)/L atm K–1)?

Why is osmotic pressure considered a colligative property?

Why is an increase in temperature observed on mixing chloroform with acetone?

What are the units of molal elevation constant?

The observed boiling point of mixture of two volatile liquids is more than that calculated. What type of deviation is noticed?

Why is CaCl2 used to remove snow on roads?

Why is freezing point depressed when a non-volatile solute is added?

Why is boiling point elevated when a non-volatile solute is added?

The osmotic pressure of polymers (Macro-molecules) are determined by osmotic pressure and not by other colligative properties. Explain.

What happens when blood cells are placed in pure water?

What are the factors on which the vapour pressure of a liquid depends?

State the conditions under which the Raoult’s law holds good.

What are the different types of azetropes? Give one example of each.

Give an example of a compound in which hydrogen bonding results in the formation of a dimer.

State any two characteristics of an ideal solution.

What are the value ΔH, ΔV and Ptotal for a solution showing negative deviation from identity? Give one example.

If the membrane used in determination of osmotic pressure is slight leaking, how will it influence the measured value of osmotic pressure?

Why do doctors advice gargles of saline water in case of soring of throat?

A person suffering from high blood pressure should take less common salt in the food. Why?

What type of deviation (+ ve or – ve) is expected of a solution obtained by adding conc. H2SO4 to water?

Which process is used in large scale desalination of sea water?

Which of the following has higher vapour pressure at same temperature: CH3OH (b. p. 640.50C) and C2H5OH (b.p. 78.30C)?

Why is the freezing point depressed when a non-volatile solute is dissolved in a liquid solvent?

Which of the two has higher osmotic pressure: 1 M glucose solution or 1 M NaCl solution at the same temperature?

Modify the equation ΔTb = Kb m using Van’t Hoff factor.

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 molarity of each of the following solution (a) 30 g of Co(NO₃)₂.6H₂O in 4.3 L solution (b) 30 mL of 0.5 MH₂SO₄ diluted to 500 mL.

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

H₂S, a toxic gas with rotten egg like smell, is used for the qualitative analysis. If the solubility of H₂S in water at S.T.P. is 0.195 m, calculate Henry's law constant.

Henry’s law constant for CO₂ in water is 1.67 x 10⁸ P_a at 298 K. Calculate the quantity of CO₂ in 500 mL of soda water when packed under 2.5 atm CO₂ pressure at 298 K.

Vapour pressure of pure water at 298 K is 23.8 mm. 50 g of urea (NH₂CONH₂) is dissolved in 850 g of water. Calculate the vapour pressure of water for this solution and its relative lowering.

Boiling point of water at 750 mm Hg 99.63⁰C. How much sucrose is to be added to 500g of water such that it boils at 100⁰C.

Calculate the mass of ascorbic acid (Vitamin C, C₆H₈O₆) to be dissolved in 75 g of acetic acid to lower its melting point by 1.5 ⁰C. K_f= 3.9 k kg mol^–1.

Calculate the osmotic pressure in pascals exerted by a solution prepared by dissolving 1.0 g of polymer of molar mass 185,000 in 450 mL at 37⁰C.

Amongst the following compunds identify which are insoluble, partially soluble and highly soluble in water?
(i) phenol (ii) toluene (iii) formic acid (iv) ethylene glycol (v) chloroform, (vi) pentanol.

Two liquids A and B boils at 145⁰C and 190⁰C respectively. Which of them has a higher vapour pressure at 80⁰C ?

What is expected value of Van’t Hoff factor for K₃ [Fe(CN)₆] in dilute solution?

What would be the value of Van’t Hoff factor for a dilute solution of K₂SO₄ in water?

In the determination of molar mass of A⁺B^– using a colligative property, what may be the value of Van’t Hoff factor if the solute is 50% dissociated?

Why is the elivation in boiling point of water different in the following solution?
(i) 0.1 molar NaCl solution.
(ii) 0.1 molar sugar solution.

What is Van’t Hoff factor i of the compound AlCl₃?

A deci-molar solution of K₄ [Fe(CN)₆] is 50% dissociated at 300 K. Calculate the osmotic pressure of solution (R = 0.082)/L atm K^–1)?

Why is CaCl₂ used to remove snow on roads?

What are the value ΔH, ΔV and P_total for a solution showing negative deviation from identity? Give one example.

What type of deviation (+ ve or – ve) is expected of a solution obtained by adding conc. H₂SO₄ to water?

Which of the following has higher vapour pressure at same temperature: CH₃OH (b. p. 640.5⁰C) and C₂H₅OH (b.p. 78.3⁰C)?

Modify the equation ΔT_b = K_b m using Van’t Hoff factor.

Define the following terms:
Mole fraction

Define the following terms:
Molality

Define the following terms:
Molarity

Define the following terms:
Mass percentage.

What is meant by positive and negative deviations from Raoult’s law and how is the sign of Δ_mix H related to positive and negative deviations Raoult’s law?

Given below is the sketch of a plant for carrying out a process.

(i) Name the process occurring in the above plant.
(ii) To which container does the net flow of solvent take place?
(iii) Name one SPM which can be used in this plant.
(iv) Give one potential use of the plant.

(a) Draw a labelled diagram to show the change in vapour pressure of a solvent, when a non-volatile solute is added to it.
(b) Show that the change in boiling point of the solvent in this diagram?

(a) What are non-ideal solution?
(b) What role does the molecular interaction play in deciding the vapour pressure of solutions (i) alcohol and kerosene (ii) Chloroform and acetone.

Explain the following phenomena:
(i) Hemolysis
(ii) Crenation.

Suggest the most important type of intermolecular attractive interaction in the following pairs.
(i) n-hexane and n-octane.
(ii) I₂ and CCl_4.(iii) NaCl O₄ and water.
(iv) methanol and acetone.
(v) acetonitrite (CH₃ CN) and acetone (C₃H₆O).

Based on solute-solvent interactions, arrange the following in order of increasing solubility in n-octane and explain cyclohexane, KCl, CH₃OH, CH₃CN.

Concentrated nitric acid used in the laboratory work is 68% nitric acid by mass in aqueous solution. What should be molarity of such sample of the acid if the density of 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 the solution is 1.2 g mL^–1, then what shall be the molarity of the solution?

How many mL of 0.1 M HC1 are required to react completely with 1 g mixture of Na₂CO₃and NaHCO₃ containing equimolar amounts of both?

An antifreeze solution is prepared from 222.6 g of ethylene glycol (C₂H₆O₂) and 200 g of water. Calculate the molality of the solution. If the density of the solution is 1.072 g mL^–1, then what shall be the molarity of the solution?

A sample of drinking water was found to be severely contaminated with chloroform (CHCl₃), supposed to be a carcinogen. The level of contamination was 15 ppm (by mass):
(i) express this in percent by mass
(ii) determine the molality of chloroform in the water sample.

The partial pressure of ethane over a solution containing 6.56 x 10^–3 g of ethane is 1 bar. If the solution contains 5.00 x 10^–2 g of ethane, then what shall be the partial pressure of th gas?

Calculate the mass of a non-volatile solute (molecular mass 40 g mol^–1) which should be dissolved in 114 g octane to reduce its vapour pressure to 80%.

If the density of some lake water is 1.25 g mL^–1 and contains 92 g of Na⁺ ions per kg of water, calculate the molality of Na⁺ ions in the lake.

If the solubility product of CuS is 6 x 10^–16, calculate the maximum molarity of CuS in aqueous solution.

Calculate the mass percentage of aspirin (C₉H₈O₄) in acetonitrile (CH₃CN) when 6.5 of C₉H₈O₄ is dissolved in 400 g of CH₃CN.

Calculate the molarity of 1 litre solution of 93% H₂SO₄ (weight/volume). The density of solution is 1.84 gm L^–1.

Calculate the amount of benzoic acid (C₆H₅COOH) required for preparing 250 mL of 0.15 M solution in methanol.

Calculate the depression in the freezing of water when 10 g of CH₃CH₂CHCICOOH is added to 250 g of water. K_a = 1.4 x 10^–3, K_f= 1.86 K kg moL^–1.

Nalorphene (C₁₉ H₂₁ NO₃) similar to morphine, is used to combat withdrawl symptoms in narcotic users. Dose of nalophene generally given is 1.5 mg. Calculate the mass of 1.5 x10^–3 m aqueous solution required for the above dose.

Henry's law constant for the molality of methane in benzene at 298 K is 4.27 x 10⁵mm Hg. Calculate the solubility of methane in benzene at 298 K under 760 mm Hg.