A lamp of marble chips was dropped in excess 0.1mol/dm hydrochloric acid and observed for sometime. (a) State what you would see. (b)Describe how the rate of reaction changed with time.
(c)Explain why the reaction stopped after sometime.
(d)The reaction was rather slow.State two ways of speeding it up.
a. bubbles
b. rxn decreases with time
c. ran how of marble chips
d.
1. incrase concn HCl
2. increase surface area of chips by breaking them apart into smaller pieces.
(a) When a lamp of marble chips is dropped in excess hydrochloric acid, you would initially observe a rapid fizzing or bubbling in the solution. This is due to the release of carbon dioxide gas as the acid reacts with the marble chips.
(b) The rate of reaction between hydrochloric acid and marble chips tends to decrease with time. Initially, the rate is high, and you would observe vigorous bubbling and a rapid reaction. However, as the reaction proceeds, the rate gradually slows down. Eventually, the bubbling will stop, indicating that the reaction has largely completed.
(c) The reaction between hydrochloric acid and marble chips stops after some time due to the consumption of one of the reactants. In this case, the marble chips (calcium carbonate) are being dissolved by the hydrochloric acid to produce calcium chloride, water, and carbon dioxide gas. As the marble chips dissolve and react with the acid, they eventually get consumed, leading to the termination of the reaction.
(d) Two ways to speed up the reaction between hydrochloric acid and marble chips are:
1. Increasing the surface area of the marble chips: By crushing the marble chips into smaller pieces or powder, you can increase their surface area. This will expose more reactant particles to the acid, leading to a higher collision rate and, hence, a faster rate of reaction.
2. Increasing the concentration or strength of the hydrochloric acid: By using a higher concentration of hydrochloric acid, there will be more acid particles available to react with the marble chips. This increases the chances of successful collisions between the reactant particles, resulting in a faster reaction.
(a) In this scenario, when a lamp made of marble chips is dropped into excess 0.1mol/dm hydrochloric acid, you would observe a series of changes:
1. Effervescence: As soon as the lamp is added to the acid, you would notice the release of gas bubbles. This gas is carbon dioxide (CO2), which is produced due to the chemical reaction between the hydrochloric acid and the marble chips.
2. Fizzing sound: Along with the effervescence, you might also hear a fizzing sound, indicating that a chemical reaction is taking place.
3. Visible reaction: The marble chips would gradually dissolve in the hydrochloric acid, causing a visible change as the lamp starts to show signs of deterioration.
(b) The rate of reaction in this case would change with time. Initially, when the lamp is dropped into the acid, the reaction rate would be relatively high. The effervescence and fizzing sound would be more pronounced, indicating a faster reaction. However, as time passes, the rate of reaction would gradually decrease. The effervescence and fizzing sound would become less intense, suggesting a slower rate of reaction.
(c) The reaction stops after some time due to the depletion of either one or both of the reactants, hydrochloric acid or marble chips. As the marble chips dissolve in the acid, they get used up and eventually become fully consumed. Once the reactants are fully consumed, the reaction stops because there are no more particles available for the reaction to proceed. At this point, the acid would no longer react with the marble chips, and no further dissolution or gas production would occur.
(d) To speed up the reaction, two methods can be employed:
1. Increase the concentration of the hydrochloric acid: By using a higher concentration of hydrochloric acid, more acid particles would be available to react with the marble chips, resulting in a faster reaction rate.
2. Increase the temperature: By heating the hydrochloric acid, the molecules would gain more kinetic energy, leading to more frequent and energetic collisions between the acid and the marble chips. This would result in an increased reaction rate.