experimental technique - controlled experiment-heat absorption of different size particles.

The same amount of gas is produced because the same amount of calcium carbonate was used in each case.

It is likley that Irene was trying to find the relationship between the size of the reactant particles and the speed of the reaction.

The variables that must be controlled are:

the same mass of calcium carbonate must be used;
the same volume of vinegar must be used;
the vinegar must be at the same temperature.
.

Irene can conclude that the smaller the reactant particles the quicker the reaction reaches completion.

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Experimental technique

Controlled experiments

Rate of reaction

Irene later tried the same experiment with 5 grams of powdered calcium carbonate. The gas that evolved was trapped in a cylinder and its volume recorded. The time for the reaction to reach completion was also recorded.

Why is the same amount of gas produced each time?

What are the variables that Irene must control when she repeats the experiment?

What was Irene trying to find?

What is her likely conclusion?

Solution

Continue with the task below

Design an experiment to find out if the temperature of the water influences the amount of gas dissolved in it.

Experimental technique Controlled experiments Rate of reaction
Irene placed a 5 gram piece of calcium carbonate in a container of vinegar. The gas that evolved was trapped in a cylinder and its volume recorded. The time for the reaction to reach completion was also recorded.
Irene later tried the same experiment with 5 grams of powdered calcium carbonate. The gas that evolved was trapped in a cylinder and its volume recorded. The time for the reaction to reach completion was also recorded. Why is the same amount of gas produced each time? What are the variables that Irene must control when she repeats the experiment? What was Irene trying to find? What is her likely conclusion? Solution
Continue with the task below Design an experiment to find out if the temperature of the water influences the amount of gas dissolved in it.