Undiluted (20ml buffer ) Volume of HCL Added Volume of NaOH PH...

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Undiluted (20ml buffer )    	 		 			Volume of HCL Added 			 			 				 			 			 			Volume of NaOH 			PH 		 		 			 			 				 			 			 			 			 				 			 			 			 			 				 			 			 			 			 				 			 			 		 		 			 			 				 			 			 			 			 				 			 			 			 			 				 			 			 			 			 				 			 			 		 		 			 			 				 			 			 			 			 				 			 			 			 			 				 			 			 			 			 				 			 			 		 		 			 			 				 			 			 			 			 				 			 			 			 			 				 			 			 			 			 				 			 			 		 		 			 			 				 			 			 			 			 				 			 			 			 			 				 			 			 			 			 				 			 			 		 		 			 			 				 			 			 			 			 				 			 			 			 			 				 			 			 			 			 				 			 			 		 	   XXXXXXXXXXml of buffer add 10.0ml of water 	 		 			Volume of HCL Added 			 			 				 			 			 			Volume of NaOH 			PH 		 		 			 			 				 			 			 			 			 				 			 			 			0.0 			 			 				 			 			 		 		 			 			 				 			 			 			 			 				 			 			 			0.1 			 			 				 			 			 		 		 			 			 				 			 			 			 			 				 			 			 			0.2 			 			 				 			 			 		 		 			 			 				 			 			 			 			 				 			 			 			0.3 			 			 				 			 			 		 		 			 			 				 			 			 			 			 				 			 			 			 			 				 			 			 			 			 				 			 			 		 		 			 			 				 			 			 			 			 				 			 			 			 			 				 			 			 			 			 				 			 			 		 	   	2.0ML of buffer add 18.0 ml of water      	 		 			Volume of HCL Added 			 			 				 			 			 			Volume of NaOH 			PH 		 		 			 			 				 			 			 			 			 				 			 			 			0.0 			 			 				 			 			 		 		 			 			 				 			 			 			 			 				 			 			 			0.1 			 			 				 			 			 		 		 			 			 				 			 			 			 			 				 			 			 			0.2 			 			 				 			 			 		 		 			 			 				 			 			 			 			 				 			 			 			0.3

Robert · Accepted Answer

BUFFER LAB 
ABSTRACT: Buffers are a compound or a mixture of compounds which is having a unique 
property to maintain the pH of a solution on the addition of small quantities of acid or alkali. 
Buffers are very important in various biological activities. The main theme of the experiment is 
to prepare a buffer solution and to measure the buffer action. The dependency of the 
concentration of buffer solution on the buffer action will also be studied. It is estimated that pH 
of the buffer remain constant even on dilution, But the buffer capacity will decrease on dilution. 
INTRODUCTION: Usually buffer solutions are the resultant of the mixing of two compounds 
together in equi-molar concentration. There are two types of buffers 1) Acid buffer- a mixture of 
a weak acid and salt of a weak with a strong base example- CH3COOH and CH3COONaand 2) 
Basic Buffer, which is mixture of weak base and salt of the weak base with a strong acid eg- 
NH4OH and NH4Cl. Acid buffers are used to maintain an acidic pH and basic buffers are used 
to maintain a basic pH. On additions of small amount of weak acid or base, these buffers resist a 
change in pH. They work by removing the pH changing ions- H+ from acid and OH- from bases 
and thus maintaining the pH. 
pH of a buffer solution can be obtained by an equation called Henderson- Hasselbach equation, 
which is expressed below. 
[ ]
log
[ ]
salt
pH pKb
base
   
EXPERIMENTAL: 
The experiment has several steps. At first the buffer solution is prepared as follows. 200 
mL buffer solution was prepared by dissolving 5.44g of KH2PO4 and 20mL 1M KOH solution 
were mixed together and diluted with deionised water to the mark in a standard measuring flask. 
After preparing the buffer solution, the buffer capacity has to be measured as follows. 20 
mL of the prepared buffer solution was added to a clean beaker and pH is measured. To this 
1.0mL of 0.1M NaOH is added from a burette and pH was measured. This was repeated 4 more 
times and pHs obtained were tabulated. After that, take again 20 mL of the buffer solution to 
another beaker, find the pH. Now add 1 mL of 0.1M HCl solution and repeat the process given 
above. The results are tabulated. 
The next aim is to find the dependency of the buffer capacity of the buffer on 
dilution.This experiment has two parts. Here the effect of dilution of buffer capacity of the buffer 
is studied. First dilution: 10 mL of buffer solution was measured suing a measuring flask and 
added to a clear beaker.

34 EXPERIMENT 4I PREPARATION AND PROPERTIES OF BUFFERS POTENTIAL HAZARDS Sofety glasses must be worn at oll times in the laboratory. While the chemicals used in this experiment qre in relatively...

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