Factors affecting reaction rate

Report 1 / 5

Hydrogen peroxide decomposes slowly at room conditions, producing water and oxygen gas.

This decomposition can be accelerated with the help of manganese dioxide catalyst, MnO2.

Which of the following is correct about the catalytic decomposition of hydrogen peroxide?

Difficulty Level: Medium

Report 2 / 5

Two sets of experiments were conducted to study the rate of reaction between zinc and hydrochloric acid. Results are recorded in a table.

Experiment	Reaction conditions	Time taken for reaction (s)
I	0.5g zinc lump + 50 cm³ hydrochloric acid 1.0 mol/dm³	75
II	0.5g zinc powder + 50 cm³ hydrochloric acid 1.0 mol/dm³	20

Why did the reaction in Experiment I take longer?

Difficulty Level: Medium

Report 3 / 5

Carbon dioxide gas results from the reaction of calcium carbonate with hydrochloric acid.

Excess calcium carbonate is added to a beaker containing 100 cm³ of dilute hydrochloric acid.

The total volume of carbon dioxide gas released with time is shown in the graph in the figure below.

Which of the following statements is correct about the MN part of the graph?

Difficulty Level: Hard

Report 4 / 5

The reaction of iron with acid is carried out in four different beakers. Which reaction in the beaker occurs at the highest rate?

Difficulty Level: Hard

Report 5 / 5

Catalysts are widely used in the chemical industry. Why are catalysts needed in the chemical industry?

Difficulty Level: Medium