Advertisements
Advertisements
Define the following terms : Molarity
Concept: Solubility >> Solubility of a Solid in a Liquid
Define the following term:
Molal elevation constant (Kb)
Concept: Colligative Properties and Determination of Molar Mass >> Elevation of Boiling Point
A solution of glucose (molar mass = 180 g mol–1) in water is labelled as 10% (by mass). What would be the molality and molarity of the solution ? (Density of solution = 1.2 g mL–1)
Concept: Colligative Properties and Determination of Molar Mass
From the given cells:
Lead storage cell, Mercury cell, Fuel cell and Dry cell
Answer the following:
(i) Which cell is used in hearing aids?
(ii) Which cell was used in Apollo Space Programme?
(iii) Which cell is used in automobiles and inverters?
(iv) Which cell does not have long life?
Concept: Batteries >> Primary Batteries
Following reactions occur at cathode during the electrolysis of aqueous silver chloride solution :
`Ag^+(aq)+e^(-)rarrAg(s)" "" "" "E^@=+0.80V`
`H^+(aq)+e^(-)rarr1/2H_2(g)" "" "" " E^@=0.00V`
On the basis of their standard reduction electrode potential (E°) values, which reaction is feasible at the cathode and why ?
Concept: Relation Between Gibbs Energy Change and Emf of a Cell
Why conductivity of an electrolyte solution decreases with the decrease in concentration ?
Concept: Conductance of Electrolytic Solutions >> Variation of Conductivity and Molar Conductivity with Concentration
Calculate ΔrG° for the reaction
Mg (s) + Cu2+ (aq) → Mg2+ (aq) + Cu (s)
Given : E°cell = + 2.71 V, 1 F = 96500 C mol–1
Concept: Relation Between Gibbs Energy Change and Emf of a Cell
Define “zero order reaction”.
Concept: Factors Influencing Rate of a Reaction
Write two factors that affect the rate of reaction.
Concept: Factors Influencing Rate of a Reaction
For a reaction : 
(i) Write the order and molecularity of this reaction.
(ii) Write the unit of k.
Concept: Factors Influencing Rate of a Reaction
The rate constant for the first-order decomposition of H2O2 is given by the following equation:
`logk=14.2-(1.0xx10^4)/TK`
Calculate Ea for this reaction and rate constant k if its half-life period be 200 minutes.
(Given: R = 8.314 JK–1 mol–1)
Concept: Temperature Dependence of the Rate of a Reaction
For the hydrolysis of methyl acetate in aqueous solution, the following results were obtained :
| t/s | 0 | 30 | 60 |
| [CH3COOCH3] / mol L–1 | 0.60 | 0.30 | 0.15 |
(i) Show that it follows pseudo first order reaction, as the concentration of water remains constant.
(ii) Calculate the average rate of reaction between the time interval 30 to 60 seconds.
(Given log 2 = 0.3010, log 4 = 0.6021)
Concept: Factors Influencing Rate of a Reaction
A first order reaction takes 30 minutes for 50% completion. Calculate the time required for 90% completion of this reaction.
(log 2 = 0.3010)
Concept: Half Life Period of a Reaction
The decomposition of NH3 on platinum surface is zero order reaction. What are the rates of production of N2 and H2 if k = 2.5 × 10−4 mol−1 L s−1?
Concept: Zero Order Reactions
Account for the following:
Cr2+ is a strong reducing agent.
Concept: General Properties of the Transition Elements (d-block)
When chromite ore FeCr2O4 is fused with NaOH in presence of air, a yellow-coloured compound (A) is obtained, which on acidification with dilute sulphuric acid gives a compound (B). Compound (B) on reaction with KCl forms an orange coloured crystalline compound (C).
(i) Write the formulae of the compounds (A), (B) and C.
(ii) Write one use of compound (C).
Concept: Some Important Compounds of Transition Elements - Oxides and Oxoanions of Metals
Complete the following chemical equation
8MnO4- + 3S2O32- + H2O →
Concept: Some Important Compounds of Transition Elements - Oxides and Oxoanions of Metals
What are the transition elements? Write two characteristics of the transition elements.
Concept: General Properties of the Transition Elements (d-block)
How would you account for the following:
Actinoid contraction is greater than lanthanoid contraction.
Concept: F-block Elements >> The Actinoids
