Kinetics of metals reacting with acids

In summary, the conversation discusses an investigation into the reactions of acids with Mg. The order of the reaction with respect to the acid was found to vary for different acids, with hydrochloric acid having an order of 2, sulphuric acid having an order of 1, and phosphoric acid having an order of 1.8. It was also mentioned that high concentrations of added salt can slow down the reaction, but small concentrations can increase the rate. The method used to determine the order of the reaction was by plotting log rate against log conc acid. However, there was difficulty in finding the order of Cl- and SO42- ions using a similar method. Suggestions were made to use thermodynamics to determine whether the reaction is
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hey. I am doing an investigation into reactions of acids with Mg. Firstly, iv investigated how order with respect to the acid varies for different acids
i found that the orders for each of the acids are:

Hydrochloric acid: 2
Sulphuric acid: 1
Phosphoric acid: 1.8

in an article, it said that: the effect of added sodium and magnesium chlorides indicated that high concentrations of added salt slow down the reaction considerably. There is other evidence that small concentrations of added sodium chloride increase the rate of reaction, and it is well known that sodium chloride solution alone is highly corrosive to magnesium, far more so than solutions of nitrates or sulphates.

how would i find out the order of the reaction with respect to Cl- ions?? someone said they did it and they got a negative order, which would make comply with what was said above.

for the orders experiment i just used a relatively simple pracitcal setup- using a range of acid concs and noting the time it took for a certain mass of Mg to disappear. Plotting log rate (=log 1/time) vs log conc acid, i determined the order by the gradient of the graph. Unfortunately, i can't think of a similar way to determine how the order of Cl- ions or SO42- ions using a similar method. thanks for any help

(apparently, i was told that by applying thermodynamics to this problem, i would be able to find out whether the reaction is SN1 or SN2...but i can't figure that one out either. any suggestions please?)

i no that iv written quite a bit and would appreciate any help.

thanks.:smile:
 
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anyone??
 
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I find your investigation into the kinetics of metals reacting with acids very interesting. It is important to understand the factors that affect the rate of a reaction, as it can have significant implications in various industries such as pharmaceuticals and chemical manufacturing.

Based on your findings, it seems that the order of the reaction with respect to the acid varies depending on the type of acid used. This could be due to the different properties of each acid, such as its strength and concentration. It would be helpful to further investigate the reasons behind these variations and how they affect the reaction.

Regarding your question about finding the order of the reaction with respect to Cl- ions, it is possible that the negative order obtained by the other person could be due to errors in their experimental setup or calculations. It would be best to repeat the experiment and compare your results with theirs to see if there are any discrepancies.

In terms of applying thermodynamics to determine whether the reaction is SN1 or SN2, it would require a deeper understanding of these mechanisms and their thermodynamic properties. I suggest consulting with a chemistry expert or doing further research on the topic to gain a better understanding.

Overall, your investigation is a good starting point, and I encourage you to continue exploring and experimenting to gain a better understanding of the kinetics of metals reacting with acids. Good luck with your research!
 

1. What is the basic process of a metal reacting with an acid?

The reaction between a metal and an acid involves the transfer of electrons from the metal atoms to the hydrogen ions in the acid. This results in the formation of metal ions and hydrogen gas, which is often seen as bubbles.

2. How does the reactivity of a metal affect its reaction with an acid?

The reactivity of a metal is directly related to its ability to lose electrons. More reactive metals, such as alkali metals and alkaline earth metals, have a stronger tendency to lose electrons and therefore react more vigorously with acids compared to less reactive metals like copper or silver.

3. What factors can influence the rate of a metal-acid reaction?

The rate of a metal-acid reaction can be influenced by various factors such as concentration of the acid, surface area of the metal, temperature, and presence of catalysts. Increasing the concentration of the acid or using a finer powder of the metal can speed up the reaction, while lower temperatures or the presence of a catalyst can slow it down.

4. Why do some metals react with acids while others do not?

The reactivity of a metal with acids depends on its position in the reactivity series. Metals above hydrogen in the series, such as magnesium and zinc, will readily react with acids to form metal salts and hydrogen gas. However, metals below hydrogen, such as copper and silver, are less reactive and do not react with most acids.

5. How is the rate of a metal-acid reaction measured?

The rate of a metal-acid reaction can be measured by monitoring the amount of hydrogen gas produced over time. This can be done by collecting the gas in a gas syringe or by measuring the change in pressure in a sealed container. The reaction rate can also be determined by measuring the change in mass of the metal or the change in pH of the acid solution.

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