how many moles of acid must be added to the blood to bring the carbonic acid/hydrogen carbonate ratio from 1:2 to 1:10?

Answer 1

H2CO3/HCO3^- = 1:2 and you want it to be 1:10
HCO3^- + H^+ ==> H2CO3

initial:
H2CO3 = 1
HCO3^- = 2
H^+ = call it 0
change:
H2CO3 = +x
HCO3^- = -x
H^+ = x

equilibrium:
H2CO3 = 1+x
HCO3^- = 2-x
H^+ = x

(1+x/2-x) = 10
solve for x then check it by substituting into H2CO3/HCO3^- and see if the new ratio is 10.