1. If alum is heated at first too strongly causing it to splatter out of the crucible what effect will this have on the determination of the water hydration?
2. If alum is heated insufficiently what effect will this have on the determination of the water hydration?
3. If not all the alum dissolves in the water before adding the Ba(NO3)2 solution, what effect will this have on the sulfate percent error determination?
4. If precipitation of BaSO4 is incomplete due to inadequate heating or insufficient time what will happen to the sulfate percent error determination? 5. If the BaSO4 ppt isn't washed adequately what effect will this have on the sulfate percent error determination?
6. If the BaSO4 ppt isn't dried completely what effect will this have on the sulfate percent error determination?
I know it is alot but I need some help. Are my answers correct? Thanks! :)
Answers:
1. The water of hydration will be will be lower because some alum was released from the crucible.
2. The water of hydration will be lower.
3. The percent of error will be higher.
4. Percent of error will be higher.
5. Percent of error will be higher.
6. Percent of error will be higher than the actual.
I don't think #1 is right so I believe you should rethink your other answers although I didn't look at them after #2. My reason for this response is
I assume the procedure went something like this.
(initial mass alum - final mass alum) = loss in mass and that is mass H2O released.
Then (mass H2O/mass sample)*100 = %H2O
Since some of the alum splattered out, the final weight is lower than it should be which makes the loss mass more which makes the apparent amount of H2O larger and that gives a larger % H2O.
#2 is right.
Here are the explanations for each question:
1. If alum is heated too strongly causing it to splatter out of the crucible, this will affect the determination of the water hydration. When alum is splattered out, it means that some of the water molecules in the alum have escaped. As a result, the remaining sample will have a lower amount of water of hydration. Therefore, your answer "The water of hydration will be lower because some alum was released from the crucible" is correct.
2. If alum is heated insufficiently, this will also affect the determination of the water hydration. When alum is not heated enough, the water molecules in the alum will not be completely removed, leading to a higher amount of water of hydration in the remaining sample. Therefore, your answer "The water of hydration will be lower" is not correct. The correct answer is "The water of hydration will be higher because not all water molecules have been removed."
3. If not all the alum dissolves in the water before adding the Ba(NO3)2 solution, this will have an effect on the sulfate percent error determination. The Ba(NO3)2 solution is added to react with the dissolved sulfate ions in the solution to form a precipitate of BaSO4. If not all the alum dissolves, it means that some of the sulfate ions are not available for reaction with Ba(NO3)2. As a result, the calculated sulfate percent error will be higher than the actual value. Therefore, your answer "The percent of error will be higher" is correct.
4. If the precipitation of BaSO4 is incomplete due to inadequate heating or insufficient time, this will also affect the sulfate percent error determination. The formation of BaSO4 precipitate relies on the complete reaction between sulfate ions and Ba(NO3)2. If the precipitation is incomplete, it means that not all sulfate ions have reacted to form BaSO4. Consequently, the calculated sulfate percent error will be higher than the actual value. Therefore, your answer "Percent of error will be higher" is correct.
5. If the BaSO4 precipitate isn't washed adequately, this will again have an effect on the sulfate percent error determination. Washing the precipitate helps remove any impurities or remaining soluble ions. If the washing is not done adequately, some impurities or soluble ions may still be present in the precipitate, leading to inaccurate determination of the sulfate content. Therefore, your answer "Percent of error will be higher" is correct.
6. If the BaSO4 precipitate isn't dried completely, this will also affect the sulfate percent error determination. Drying the precipitate helps remove any remaining water molecules that might be adsorbed on the surface of the precipitate. If the precipitate is not dried completely, it will still contain some water, leading to an overestimated amount of sulfate. Therefore, your answer "Percent of error will be higher than the actual" is correct.
Overall, your answers are mostly correct, but there are a few corrections needed as mentioned above.