Question 1: Define a catalyst and explain its role in a chemical reaction.

Answer: A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process, by providing an alternative reaction pathway with lower activation energy.

Question 2: Describe how a catalyst affects the activation energy of a reaction.

Answer: A catalyst lowers the activation energy required for a reaction, making it easier and faster for reactants to convert into products.

Question 3: Explain why catalysts are not consumed during a reaction.

Answer: Because catalysts provide an alternative pathway with lower activation energy without being used up in the reaction, they remain unchanged at the end.

Question 1: A reaction without a catalyst takes 20 minutes to complete. When a catalyst is added, the reaction time decreases to 5 minutes. Calculate the factor by which the reaction rate increases due to the catalyst.

Answer: The reaction rate increases by a factor of 4, since reaction rate is inversely proportional to time, calculated as 20/5 = 4.

Question 2: If the initial concentration of reactants is 0.5 mol/L and the reaction rate doubles when the concentration increases to 1.0 mol/L, what is the order of the reaction with respect to concentration?

Answer: The reaction is first order with respect to concentration, because doubling concentration doubles the rate.

Question 1: Describe an outline of an experiment to test the effect of a catalyst on the rate of decomposition of hydrogen peroxide.

Answer: Set up two test tubes with equal amounts of hydrogen peroxide, add a catalyst such as manganese dioxide to one, leave the other as control. Measure the time taken for the reaction to complete in each, noting the formation of oxygen gas as an indicator.

Question 2: Identify the variables that should be kept constant in the above experiment.

Answer: Temperature, concentration of hydrogen peroxide, amount of catalyst used, and volume of solution.

Question 3: List two safety precautions to consider when working with catalysts and reactive chemicals.

Answer: Wearing safety goggles and gloves to protect against splashes or fumes, and working in a well-ventilated area.

Question 1: A study shows that adding a certain catalyst increases the reaction rate by 300%. Explain what this means in terms of reaction time and efficiency.

Answer: An increase of 300% in reaction rate means the reaction occurs four times faster, significantly improving efficiency and reducing reaction time.

Question 2: In an industry process, a catalyst was found to be effective only within a specific temperature range. Explain why temperature affects catalytic activity.

Answer: Temperature affects the kinetic energy of molecules; too low slows reactions, while too high can deactivate the catalyst or cause unwanted side reactions, so optimal temperature ensures maximum catalytic efficiency.

Question 1: Describe how catalytic converters in cars help reduce pollution.

Answer: Catalytic converters contain catalysts that convert harmful gases like carbon monoxide, nitrogen oxides, and hydrocarbons into less harmful substances such as carbon dioxide, nitrogen, and water vapor.

Question 2: Identify one industrial process that relies heavily on catalysts and explain its importance.

Answer: The Haber process for synthesizing ammonia uses iron catalysts, which are crucial for producing fertilizers that support global food production.

Question 1: Explain how catalysts influence the energy profile of a chemical reaction and discuss their significance in industrial applications.

Answer: Catalysts provide an alternative pathway with lower activation energy, which reduces the energy barrier for the reaction. This results in faster reaction rates at lower temperatures, saving energy and cost. In industry, catalysts are vital for increasing efficiency, reducing waste, and enabling reactions that would otherwise require extreme conditions. They are essential in manufacturing processes such as oil refining, pharmaceuticals, and pollution control.