Oquizy

Xinyi is testing rate of reaction for an unknow solid. She uses sample A (powdered solid) and sample B (same mass, large lumps) and obtains this graph.
Which conclusion is correct?

More powder means more product Powder reacts slower Powdered reactant increases rate Surface area has no effect on rate

In the iodine clock experiment, a fixed amount of sodium thiosulfate and starch is added to acidified hydrogen peroxide and potassium iodide. The time taken for the solution to turn blue is recorded.
How is the rate of reaction determined in this experiment?

Measuring how much iodine is produced Measuring the final temperature Measuring the pH change of the solution Measuring the time taken for blue-black colour to appear

What does this show?

Activation energy is lower at higher temperature Fewer particles have energy to react at higher temperature Higher temperature increases activation energy More particles have enough energy to react at higher temperature

What does this graph show about catalyst?

Catalysts increase activation energy Catalysts make reactions slower Catalysts provides a more efficient reaction pathway Catalysts reduce activation energy needed

What does this graph suggest if A and B has the same volume?

A had higher concentration of reactants A used a catalyst B used powdered reactants B was done at a higher temperature

What conclusion can be made?

Higher temperature increases reaction rate Rate decreases with temperature Reaction becomes reversible at 50°C Temperature has no effect

Quiz: Chemistry - Rate Of Reactions