[highflier]

1.)  What is the principle involved, type equation, sample equation, and brief explanation involved in adding drops of FORMALDEHYDE, BENZALDEHYDE, ACETALDEHYDE and ACETONE to SODIUM HYDROXIDE?

2.) A test tube with 2ml of 40% NaOH solution is added with 5 drops of bezaldehyde then  submerging this tube in a water bath for 10 mins. upon removing it in water bath, we acidified it with 6N HCl.

What is the purpose of acidification of a sample with HCl?

Anyone please answer me you may submit LINKS, or anything THANK YOU!
I would be grateful if you can answer atleast one of my questions  

[StuffedMatt]

We have the same problem. :/ From what section are you?

[discodermolide]

1.)  What is the principle involved, type equation, sample equation, and brief explanation involved in adding drops of FORMALDEHYDE, BENZALDEHYDE, ACETALDEHYDE and ACETONE to SODIUM HYDROXIDE?

2.) A test tube with 2ml of 40% NaOH solution is added with 5 drops of bezaldehyde then  submerging this tube in a water bath for 10 mins. upon removing it in water bath, we acidified it with 6N HCl.

What is the purpose of acidification of a sample with HCl?

Anyone please answer me you may submit LINKS, or anything THANK YOU!
I would be grateful if you can answer atleast one of my questions  

Look up the Canizzaro reaction and the aldol reaction.
in question 2; HCl is used to neutralise the excess base and re-protonate one of the products.

[highflier]

Look up the Canizzaro reaction and the aldol reaction.
in question 2; HCl is used to neutralise the excess base and re-protonate one of the products.

THANKS SIR.  

[Zwrei]

Guys, I still can't understand this. I'm sorry but can someone please answer this questions for me? It can only be an idea or something. I'll appreciate that.

[discodermolide]

Guys, I still can't understand this. I'm sorry but can someone please answer this questions for me? It can only be an idea or something. I'll appreciate that.

Look at the answer above:

http://www.chemicalforums.com/index.php?topic=46051.0

[orgopete]

Deleted, I misunderstood question.

[selym2]

I have the same problem too, can anyone please help me 

[discodermolide]

Read the thread above!

[selym2]

E. Reactions of the Aldehydes and Ketones with Sodium Hydroxide

Objective:

•   To determined what physical and chemical changes happen to Aldehydes and Ketones as it react with the Sodium Hydroxide

Procedures:

1.   Prepare 5 clean and dry test tubes
2.   Label the first 3 tubes and place 2 ml 40% NaOH solution
3.   Label the remaining test tubes 4 and 5 and place 2 ml of 10% NaOH solution
4.   Transfer 10 drops of the following samples: tube 1- formaldehyde, tube 2- benzaldehyde, tube 3 & 4 acetaldehyde and in tube 5 acetone
5.   Transfer all tubes in a boiling water bath for 10 minutes: Note for the following changes:
6.   Place some 6N HCl in tube 2 after acidification
7.   Record all of your observation

Results:

Tube Sample   NaOH   Observations
Formaldehyde   40%   Foul smell
Benzaldehyde   40%   White precipitate, yellow oil on the surface of the solution
Acetaldehyde   40%   Dark Orange solution with dark resin
Acetaldehyde   10%   Orange Solution with red Precipitate
Acetone   10%   Viscous colorless Solution

Interpretation of Results:

After adding
Reagents used:

•   Sodium Hydroxide solution
•   HCl


a.)   State the function of the sodium hydroxide in the test

b.)   What are the principles involved in the test? What is its purpose

•   Cannizzaro reaction is a redox reaction in which two molecules of an aldehyde are reacted to produce a primary alcohol and a carboxylic acid using a hydroxide base. It involves a reaction with aldehydes which have no alpha hydrogen atoms

Aldol Condesation is an organic reaction in whichan enolate ion reacts with a carbonyl compound to form a β-hydroxyaldehyde or β-hydroxyketone, followed by dehydration to give a conjugated enone
•   
c.)   Provide the type equation used in the test

d.)   Show the sample equations involved in the reaction between:

•   40% Sodium Hydroxide and your samples which gave a positive result
•   10% Sodium Hydroxide and your samples which gave a positive result

e.)   Provide a possible explanation for

•   Positive result obtained with your sample


•   Negative results obtained with your samples

f.)   What is the purpose of acidification with HCL

HCl is used to neutralize the excess base and to re-protonate one of the products

please answer the following, im begging all of you.please don't ignore this.   

[discodermolide]

Why should we do all the work for you?
Forum rules state you must show your own attempt.
I suggest you start with one question at a time, otherwise the whole thing will get very confusing.