Announcements An error was encountered in experiment 2aii in both Model 1 and 2 experiment due to poor quality of filter paper used. We have taken our time to redo the experiment. Please the correction is given below Test Filtrate + Litmus papers. Observations Filtrate had no effect on both blue and red litmus papers Inference. Filtrate is neutral Thanks
Announcements Final Review As the examination is few hours from now, we make the following final review 1. If the question says: 'C' is a mixture of two soluble salts (with emphasis on the word soluble), then our observation and inference on the table for question 2ai as presented in the table is correct. This is because the students have been given a clue as to the the solubility of the salts in the sample 'C' 2. However if the question states that 'C' is a mixture of two salts (without specifying the term 'soluble'), then our observation and inference should go thus Observation: C partly dissolved in water. Filtrate is colourless and residue is white. Inference: C is a mixture of soluble and insoluble salts. This is because the students had no idea of constituents of C nor their properties 3. We had already made correction on question 2aii due to the poor quality of filtrate paper used. Test: filtrate + litmus papers Observation: filtrate had no effect on both blue and red litmus papers. Inference: Filtrate is neutral Good luck in your exams
Thank you very much sir. I'm a chemistry teacher and i must say you are spot on in everything you said. Practical is different from theory. Although i got 10.4 from my experiment, i now know why. Thank you very much for your good work.
Sir, what if our teacher gives us 18.1 as the average volume of acid,what do i do.. Since am not allowed to alter whats already jn the teachers report....
Whatever your teacher gives as end point even if it is 18.10 cm3, use it. Students of any given school are marked according to the end point given by the teacher. The end point of School A must no agree with that of B. WAEC does not provide a common end point for all schools. Hence each school has its own end point. Don't deviate from your teacher's own, whether he is right or wrong. Whatever he writes on the report sheet is correct for his students
Experiment can be done in groups most especially if you have a large number of students or if you have limited resources. The ideal arrangement is maximum of 5 students per group. However teach your students how to build their tables with different titre values and still arrive at the same end point so that it will not look as if they copied the same thing even if they are in the same group because the report form has no provision for you to indicate that they are grouped. For instance a student can have F.B.R. of 11.10 cm3 I.B.R of 1.00 cm3 Titre = 10.10 cm3 Another of the same group can have F.B.R of 18.10 cm3 I.B.R of 8.00 cm3 Titre = 10.10 cm3 So, you see they arrived at the same end point even though they are in the same or different groups eliminating the suspicion of copying from each other. Thanks
The analysis is done for you to understand the theoritical reactions. Please you don't need to report the analysis at all. You report only what is presented on the table. Thanks
You are right but should we report wrongly. Assuming am teaching students this practical, I may start by telling them that C is a mixture of salt X and Y and both salts are soluble in water. They would know that there must be precipitation reaction if they already know what it is. The confusion here is that both salts are white and the precipitate is also white. Had it been that the precipitate is of another colour, then it would be very glaring that there was a reaction and the precipitate is a different compound from the components of the mixture. Thanks
![เจ้าผู้เดียว - ดิด คิตตี้ [OFFICIAL MV]](http://i.ytimg.com/vi/q0NLCYKBOTo/mqdefault.jpg)
Announcements
An error was encountered in experiment 2aii in both Model 1 and 2 experiment due to poor quality of filter paper used. We have taken our time to redo the experiment. Please the correction is given below
Test
Filtrate + Litmus papers.
Observations
Filtrate had no effect on both blue and red litmus papers
Inference.
Filtrate is neutral
Thanks
Announcements
Final Review
As the examination is few hours from now, we make the following final review
1. If the question says: 'C' is a mixture of two soluble salts (with emphasis on the word soluble), then our observation and inference on the table for question 2ai as presented in the table is correct. This is because the students have been given a clue as to the the solubility of the salts in the sample 'C'
2. However if the question states that 'C' is a mixture of two salts (without specifying the term 'soluble'), then our observation and inference should go thus
Observation: C partly dissolved in water. Filtrate is colourless and residue is white.
Inference: C is a mixture of soluble and insoluble salts.
This is because the students had no idea of constituents of C nor their properties
3. We had already made correction on question 2aii due to the poor quality of filtrate paper used.
Test: filtrate + litmus papers
Observation: filtrate had no effect on both blue and red litmus papers.
Inference: Filtrate is neutral
Good luck in your exams
Thank you very much sir. I'm a chemistry teacher and i must say you are spot on in everything you said. Practical is different from theory. Although i got 10.4 from my experiment, i now know why. Thank you very much for your good work.
You are good to go my brother. You have done well
these videos are really helpful. I hope and pray get at least A1 in chemistry.👍👍
You will make it. Thanks
Ok,sir
Sir, what if our teacher gives us 18.1 as the average volume of acid,what do i do..
Since am not allowed to alter whats already jn the teachers report....
Whatever your teacher gives as end point even if it is 18.10 cm3, use it. Students of any given school are marked according to the end point given by the teacher. The end point of School A must no agree with that of B. WAEC does not provide a common end point for all schools. Hence each school has its own end point. Don't deviate from your teacher's own, whether he is right or wrong. Whatever he writes on the report sheet is correct for his students
Can the experiment be done in groups or must the teacher prepare the solutions for each student?? I anticipate your answer sir. Thank you
Experiment can be done in groups most especially if you have a large number of students or if you have limited resources. The ideal arrangement is maximum of 5 students per group. However teach your students how to build their tables with different titre values and still arrive at the same end point so that it will not look as if they copied the same thing even if they are in the same group because the report form has no provision for you to indicate that they are grouped.
For instance a student can have
F.B.R. of 11.10 cm3
I.B.R of 1.00 cm3
Titre = 10.10 cm3
Another of the same group can have
F.B.R of 18.10 cm3
I.B.R of 8.00 cm3
Titre = 10.10 cm3
So, you see they arrived at the same end point even though they are in the same or different groups eliminating the suspicion of copying from each other. Thanks
Sir,is the analysis to be done on a rough sheet or beside the inference
The analysis is done for you to understand the theoritical reactions. Please you don't need to report the analysis at all. You report only what is presented on the table. Thanks
Morning.
Will the Analysis Need to be written down in the exam?
Or can we be asked to weite down the analysis for each Test?
Please don't write the analysis in the examination. It was only done to explain the results of the experiment
You will not be asked to do so
IF YOU SAY C IS A MIXTURE TWO SOLUBLE SALTS. IT MEANS YOU HAVE A PRIOR KNOWLEDGE OF C.
You are right but should we report wrongly. Assuming am teaching students this practical, I may start by telling them that C is a mixture of salt X and Y and both salts are soluble in water. They would know that there must be precipitation reaction if they already know what it is. The confusion here is that both salts are white and the precipitate is also white. Had it been that the precipitate is of another colour, then it would be very glaring that there was a reaction and the precipitate is a different compound from the components of the mixture. Thanks