Question

Mr. Rajesh assumed that the time taken for 10 cm of CO2 to be formed from a reaction between equal volume
of acid solutions and 1.0 g of calcium carbonate is affected by the pH of acid solution. Mr. Rajesh tested his hypothesis and represented his results in the graph
below.
(1) Will lumps of CaCO, react faster or slower than powdered CaCO3?
(ii) What will be time taken to collect 10 cm. of Co2 at pH = 5.0?
(iii) What is the nature of CaCO, salt and what will happen if acid with pH = 6,5 is added to CaCO^3? ​

Answer 1

Answer:

1. it will react slower than powdered caco3
2. it will take 60mins
3. the nature is calcium carbonate . the acid will turn into blue litmus

Explanation:

Answer 2

1. Lumps of calcium carbonate will act slower than powdered calcium carbonate.

2. 40 secs as inferred from the graph.

3.Calcium carbonate is a basic salt. If an acid with pH 6.5 is added to it, neutralisation reaction occurs with carbon dioxide and water as byproducts.

• Lumps of carbon dioxide will offer lesser surface area for it to interact with an acid as compared to the fine texture of powdered carbon- dioxide making it easier and more feasible to involve in experiments.

• As inferred from the graph,( first see the Y axis and notice the pH required, then move your finger along with the line corresponding and see where it joins the X axis and notice the time taken),it will take us 40 secs to collect 10 cm of carbon dioxide with pH 5.

• Calcium carbonate is a basic salt, and when an acid is added to it a neutralisation reaction occurs with a gaseous byproduct usually CO$_{2}$and water is formed .

                                      $CaCO_{3}$ + $HX$ ⇄ $CaX$+$CO_{2}$ + $H_{2}O$