Chemistry Class 12 CBSE

What is the rate determining step in a chemical reaction?

• The rate determining step is the first step in the reaction mechanism.

• The rate determining step is the step with the lowest concentration of products.

• The rate determining step in a chemical reaction is the slowest step in the reaction mechanism.

• The rate determining step is the step with the highest concentration of reactants.

Explain the concept of half-life in the context of chemical kinetics.

• Half-life is the time it takes for a reactant to increase by half

• Half-life in chemical kinetics refers to the time it takes for the concentration of a reactant to decrease by half.

• Half-life refers to the time it takes for a reaction to complete

• Half-life only applies to biological processes, not chemical kinetics

What is the Nernst equation and how is it used in electrochemistry?

• The Nernst equation is used to calculate the equilibrium potential of a cell or half-cell in electrochemistry by taking into account the concentration of reactants and products, as well as the temperature and the gas constant.

• The Nernst equation is used to measure the resistance of a cell in electrochemistry

• The Nernst equation is used to determine the color of a solution in electrochemistry

• The Nernst equation is used to calculate the speed of chemical reactions in electrochemistry

Discuss the significance of standard hydrogen electrode in electrochemical cells.

• The standard hydrogen electrode is not important in electrochemical cells as it does not affect the overall reaction

• The significance of the standard hydrogen electrode in electrochemical cells is that it provides a reference point for measuring the electrode potential of other half-cells.

• The standard hydrogen electrode is only used in laboratory experiments and has no practical significance

• The standard hydrogen electrode is used to generate electricity in electrochemical cells

What are biomolecules and why are they important in living organisms?

• Biomolecules are essential for life as they serve as the building blocks of cells, provide energy, and carry out essential functions such as DNA replication and protein synthesis.

• Biomolecules are harmful to living organisms

• Biomolecules are only important for non-living organisms

• Biomolecules are not involved in any cellular functions

Explain the structure and function of carbohydrates in biomolecules.

• Carbohydrates are not important for energy storage or providing structural support.

• Carbohydrates are inorganic molecules composed of carbon, hydrogen, and nitrogen.

• Carbohydrates serve as a primary source of protein for living organisms.

• Carbohydrates are organic molecules composed of carbon, hydrogen, and oxygen. They serve as a primary source of energy for living organisms and play a structural role in cells. Carbohydrates can be simple sugars, such as glucose, or complex molecules like starch and cellulose. They are important for energy storage, providing structural support, and serving as a component of nucleic acids and cell surface markers.

What are enzymes and how do they catalyze biochemical reactions?

• Enzymes are only found in plants and do not play a role in biochemical reactions.

• Enzymes are biological molecules that speed up biochemical reactions by lowering the activation energy required for the reaction to occur.

• Enzymes are a type of hormone that inhibits biochemical reactions by blocking the active sites of substrates.

• Enzymes are inorganic substances that slow down biochemical reactions by increasing the activation energy required for the reaction to occur.

Discuss the role of nucleic acids in storing and transmitting genetic information.

• Nucleic acids store and transmit genetic information through their protein structure.

• Nucleic acids store and transmit genetic information through their lipid composition.

• Nucleic acids store and transmit genetic information through their sequence of nucleotides.

• Nucleic acids store and transmit genetic information through their carbohydrate content.

What are the different types of electrochemical cells and how do they work?

• The different types of electrochemical cells are galvanic cells and electrolytic cells. Galvanic cells convert chemical energy into electrical energy through spontaneous redox reactions, while electrolytic cells use electrical energy to drive non-spontaneous redox reactions.

• The different types of electrochemical cells are solar cells and fuel cells. Solar cells convert sunlight directly into electricity, while fuel cells use hydrogen and oxygen to produce electricity.

• The different types of electrochemical cells are voltaic cells and voltaic cells. Voltaic cells convert chemical energy into electrical energy through spontaneous redox reactions.

• The different types of electrochemical cells are anode cells and cathode cells. Anode cells convert electrical energy into chemical energy, while cathode cells use chemical energy to produce electricity.

Compare and contrast the different methods for determining the rate of a chemical reaction.

• The temperature of the reactants

• The volume of the reactants

• The different methods for determining the rate of a chemical reaction include initial rate method, continuous monitoring method, and integrated rate method.

• The color of the reactants