The pH of milk, black coffee, tomato juice, lemon juice and egg white are 6.8, 5.0, 4.2, 2.2 and 7.8 respectively. Calculate corresponding hydrogen ion concentration in each.

The pH of milk, black coffee, tomato juice, lemon juice and egg white

1.	The pH of milk, black coffee, tomato juice, lemon juice and egg white are 6.8, 5.0, 4.2, 2.2 and 7.8 respectively. Calculate corresponding hydrogen ion concentration in each.
Answer» Solution :(i)Calculation of `[H^+]` in milk [pH=6.8] pH=-log `[H^+]`=6.8 = `bar7.2` `therefore [H^+]` = Antilog `(bar7.2)=1.5849xx10^(-7)` `approx 1.58xx10^(-7)` M (II)`[H^+]` CONCENTRATION in BLACK coffee [pH=0.5] pH=-log `[H^+]`-5.0 and log `[H^+]`=-5 So, `[H^+]` = Antilog `[H^+]` =Antilog (-5) `=1xx10^(-5)` M (iii)Concentration of `[H^+]` in tomato juice [pH=4.2] pH=-log `[H^+]` =4.2 log `[H^+]`=-4.2 = `bar5.8` `therefore [H^+]` Antilog `(bar5.8)=6.3096xx10^(-5)` `approx 6.31xx10^(-5)` M (iv)concentration of `[H^+]` in lemon juice [pH=2.2] pH=-log `[H^+]` = 2.2 `therefore` log `[H^+]` = 2.2 =`bar3.8` `therefore [H^+]` =Antilog `(bar3.8)=6.3096xx10^(-3)` `approx 6.31xx10^(-3)` M (v) Concentration of `[H^+]` in egg white [pH=7.8] pH =-log `[H^+]`=7.8 `therefore` log `[H^+]`=-7.8 =`bar8.2` `therefore [H^+]`=Antilog `(bar8.2)=1.5849xx10^(-8)` `approx 1.58xx10^(-8)` M