Curriculum-aligned Chemistry questions for Class 12 under CBSE. Shortlist topics, practice at your pace, and make every answer count.
A reaction between two reactants follows first-order kinetics, and the student is required to derive the integrated rate equation for this reaction. Given the initial concentration and the rate constant, calculate the concentration of the reactant after a specified time period. Illustrate how the Arrhenius equation can be used to determine the activation energy of the reaction from experimental data and discuss the implications of this energy on the rate of reaction.
In an experiment, a student investigates the general properties of transition elements by comparing the reactivity of iron, copper, and nickel with dilute hydrochloric acid. Discuss the observed differences in reactivity, considering factors such as oxidation states, electronic configuration, and the presence of d-orbitals. Explain how these factors contribute to the unique chemical behavior of transition metals in this context.
A chemistry student is tasked with synthesizing a complex coordination compound using Werner's theory as a guiding principle. Describe how the theory can be applied to predict the geometry and coordination number of the compound formed. Include examples of different coordination numbers and their corresponding geometries. Discuss how the nature of the central metal ion and the ligands influence the properties of the coordination compound.
A fuel cell operates by converting the chemical energy from a reaction between hydrogen and oxygen into electrical energy. In this context, consider a fuel cell that utilizes a molar solution of sulfuric acid as an electrolyte. If the fuel cell requires a specific molarity for optimal performance, describe how you would prepare a 2.0 M solution of sulfuric acid (H2SO4) starting from concentrated sulfuric acid (which has a density of 1.84 g/mL and a concentration of 18.0 M). Show your calculations clearly and explain the concepts of molarity and dilution involved in this preparation. Additionally, discuss the significance of this molarity in relation to the efficiency of the fuel cell operation.
In a laboratory experiment, a chemist prepared a solution by dissolving a certain mass of potassium nitrate (KNO3) in water. The mass of KNO3 used was 45 grams, and the final volume of the solution was adjusted to 500 mL. Calculate the molarity of the potassium nitrate solution. Furthermore, if the chemist were to dilute this solution to a final volume of 1.5 L, what would be the new molarity of the solution? Discuss how changes in concentration affect colligative properties such as boiling point elevation and freezing point depression, providing relevant equations for your explanation.
A solution is prepared by mixing 100 g of NaCl in 500 g of water. Calculate the molality and mole fraction of NaCl in the solution.
A solution of a non-volatile solute in benzene shows a boiling point elevation of 2°C. If the ebullioscopic constant of benzene is 2.53°C kg/mol, calculate the molality of the solution.
During electrolysis of water, if the current is 2 A and the electrolysis time is 30 minutes, calculate the volume of hydrogen gas produced at STP. (Use Faraday's laws of electrolysis and assume 100% efficiency.)
Describe the differences between Valence Bond Theory and Crystal Field Theory in terms of their approach to explaining the bonding in coordination compounds.
A certain reaction has an activation energy of 75 kJ/mol. Calculate the rate constant at 300 K using the Arrhenius equation, given that the pre-exponential factor A is 1.5 x 10^12 s^-1.
A reaction follows first-order kinetics. If the rate constant k is 0.1 s^-1, calculate the time required for the concentration of the reactant to reduce to half of its initial value.
A transition metal shows an electronic configuration of [Ar] 3d^5 4s^2. Identify this metal and explain its position in the d-block elements.
A solution exhibits a boiling point elevation of 2.5 °C. Calculate the molality of the solution if the ebullioscopic constant (Kb) of the solvent is 0.52 °C kg/mol. Show your calculation steps.
If the conductivity of a solution increases with the dilution of the electrolyte, explain this phenomenon and relate it to the concepts of conductance and conductivity.
Study the given molecular structure and write the molecular formula represented by it.
In a reaction where the rate is proportional to the concentration of one reactant raised to the second power, classify the reaction order and explain how to determine the rate constant from experimental data.
A transition metal ion has the electronic configuration [Ar] 3d^5 4s^2. Identify the element and discuss its possible oxidation states based on this configuration.
Which theory helps explain the bonding in coordination compounds involving d-orbitals?
What is the correct nomenclature for the complex ion [Cu(NH3)4]2+?
Which application of coordination compounds is commonly used in medical diagnostics?