A student used 5.06g of copper sulphate pentahydrate and salicyclic acid in the performance of the experiment. The student recovered 3.094g of salicyclic acid and 2.146g of copper sulphate pentahydrate. What is wrong with the student's result? How might this error have been avoided?
Mayebe it depends on hw de experiment was carried out. Maybe he did not do it the apporiate way
and made him to loose some of the mixture so when he weighed it , it gave him a different weight. My oppinion tho🤷
Mayebe it depends on hw de exoeriment was carried out. Maybe he did not do it the apporiate way and made him to loose some of the mixture so when he weighed it , it gave him a different weight
The student's result seems to indicate that the amount of salicylic acid recovered is greater than the amount of copper sulphate pentahydrate used. However, this is chemically impossible as the reactants used in the experiment should ideally be present in a stoichiometric ratio.
To determine what went wrong, we need to consider the balanced chemical equation for the reaction between copper sulphate pentahydrate and salicylic acid:
Copper Sulphate Pentahydrate + Salicylic Acid → Copper Salicylate + Sulphuric Acid + Water
From the equation, we can see that 1 mole of copper sulphate pentahydrate should react with 2 moles of salicylic acid to form other products. Therefore, the molar ratio of copper sulphate pentahydrate to salicylic acid is 1:2.
To find the theoretical amount of salicylic acid that should have been recovered, we can use stoichiometry:
1 mole of Copper Sulphate Pentahydrate = 5.06g
2 moles of Salicylic Acid = ?
To calculate the molar amount of salicylic acid:
1. Convert the mass of Copper Sulphate Pentahydrate to moles using its molar mass.
Molar Mass of Copper Sulphate Pentahydrate = (63.55 + 32.07 + (4 x 16.00) + (5 x 1.01)) g/mol
Molar amount of Copper Sulphate Pentahydrate = 5.06g / Molar mass of Copper Sulphate Pentahydrate
2. Use the molar ratio from the balanced equation to find the molar amount of salicylic acid.
Molar amount of Salicylic Acid = 2 x Molar amount of Copper Sulphate Pentahydrate
Once we know the theoretical amount of salicylic acid that should have been recovered, we can compare it with the actual amount of salicylic acid obtained (3.094g). If the actual amount is less than the theoretical amount, it suggests that there was a loss of salicylic acid during the experiment.
Possible sources of error in this experiment could include:
1. Incomplete reaction: It is possible that the reaction did not go to completion, leading to a lower yield of salicylic acid.
2. Loss of product during filtration: If the filtration process was not performed properly, some of the salicylic acid crystals could have been lost.
3. Contamination: If there was contamination from impurities or other substances, it could affect the accuracy of the results.
To avoid these errors, the student could have taken the following measures:
1. Ensure complete reaction: Allow the reaction to proceed for a sufficient amount of time to ensure complete conversion of reactants to products.
2. Optimize filtration: Use proper filtration techniques to ensure minimal loss of product during the filtration process.
3. Maintain purity: Ensure that all apparatus and reactants used in the experiment are clean and free from impurities to avoid contamination.
By handling these considerations, the student can improve the accuracy of their results and obtain a more reasonable yield of salicylic acid.