In an experiment, calcium carbonate reacted with different volumes of hydrochloric acid in water. One of the products formed during the experiment was carbon
dioxide. The time taken for 0.89 mL of carbon dioxide to form was recorded. A partial record of the experiment is shown
Flask
Experimental Record
Mass of Volume of Volume of
Calcium Carbonate HCI Water
Time
1
4.0 g
25 ml
0 mL
11.2 seconds
2
4.09
20 mL
5 mL
3
4.09
15 ml
10 ml
4
4.0 g
10 ml
15 ml
Based on your knowledge of factors that affect the rates of chemical reactions, predict the trend in the last column of the experimental record. Use complete
sentences to explain the trend you predicted. You do not have to determine exact values for time; just describe the trend you would expect (increase or decrease)
and why it occurs.

The time in the last column increases steadily

Explanation:

Now let us look at the values presented in the table in the light of the facts that we already know in chemistry.

We already know that the rate of reaction (depicted by the time taken for 0.89 mL of carbon dioxide to evolve) depends on the amount of reactants present.

If we look at the volume HCl and the volume of water, we will notice that the volume of HCl decreases while the volume of water increases meaning that the solution became more dilute(concentration of the solution decreases).

Hence, the time taken for 0.89 mL of carbon dioxide to evolve also increases steadily because rate of reaction decreases with decrease in concentration.

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3