A 7.2 ´ 10-3 M solution of acetic acid is 5.0% dissociated. In a 7.2 ´ 10-4 M solution, the percentage of dissociation would be

Question

A 7.2 ´ 10-3  M solution of acetic acid is 5.0% dissociated. In a 7.2 ´ 10-4 M solution, the percentage of dissociation would be	
Value 		
A.      The same. 	  	 
B. 	>5%. 		   	 
C. 	<5%. 		  	 
D. 	zero. 		  	 
E. 	none of these.

pls explain why the answer is B

DrBob222 · Answer

I would answer this based on Le Chatelier's principle.
CH3COOH + HOH ==> H3O^+ + CH3COO^-

As one adds water, the reaction is shifted to the right. Therefore, the weak acid means more water added which means more ionization.