Complete the table below.

Question

Conjugate acid		Conjugate Base
formula	Ka	formula	Kb
______	_____	C5H5N	1.7 x 10-9
H2CO3	4.5 x 10-7	_____	_____
HCN	4.9 x 10-10	_____	_____

Round each of your entries to 2 significant digits. You may assume the temperature is 25 C. 

Answer 1

As mentioned in a previous answer to a similar question posted by you, the relationship between a conjugate acid and base pair is simply the presence/absence of a hydrogen atom. The relationship between Ka and Kb is Ka x Kb = 1x10^-14. With this information in mind, you can fill in the table as follows:

Conjugate acid		Conjugate Base
formula	Ka	formula	Kb
C5H5NH+	5.9x10-6	C5H5N	1.7 x 10-9
H2CO3	4.5 x 10-7	HCO3-	2.2x10-8
HCN	4.9 x 10-10	CN-	2.0x10-5