When you are given multiple Ka or Kb values (like Ka step one , Ka dos , Ka 3 ), you can also combine them together into an overall Ka or Kb by multiplying them together. The equations below display what I mean.
If Mg(OH) 2 has a Kb 1 of 0.3 profily apex and a Kb 2 of cuatro.5 * 10 -3 what is the over all Kb value?
If the Become(OH)
If H 3 PO 4 has a Ka 1 of 2.8 * 10 -3 and a Ka 2 of 7.1 * 10 -6 . 3 if the overall Ka is 7.75 * 10 -17 ?
Answer: ( 2.8 * 10 -3 ) * ( 7.1 * 10 -6 ) * Ka 3 = 7.75 * 10 -17
If Al(OH) 3 has a Kb 1 of 0.04 and a Kb 2 of 5.1 * 10 -4 what is the over all Kb value?
If H 2 SO 4 has a Ka 1 of 15 and a Ka 2 of 2.0 * 10 -2 . Then what is the over all Ka value?
If H 3 PO 3 has Ka 2 of 4.7 * 10 -5 and a Ka 3 of 2.3 * 10 -8 . 1 if the overall Ka is 5.5 * 10 -16 ?
Answer: Ka1 * (4.7 * 10 -5 ) * (2.3 * 10 -8 ) = 5.5 * 10 -16 — Ka1 = 5.09 * 10 -4
2 has a Kb 1 of 3.6 * 10 -4 and an overall Kb of 8.2 * 10 -12 what would be the Kb 2 ?
Answer: (3.6 * 10 -4 ) * Kb 2 = 8.2 * 10 -12 — Kb 2 = 2.24 * 10 -8
It turns out you to definitely Ka and you can Kb are about that various other when you look at the a formula. This algorithm enables you to convert off Ka so you’re able to Kb and you can vise versa. The brand new formula was found less than .
The fantastic thing about that it algorithm can it be including permits you to help you expect whether something is an acid or a bottom . How you can contour whether some thing is actually an acidic otherwise ft just by its Ka or Kb worthy of is to contrast it on the harmony lingering to have water such as the brand new equation less than.
In case your Ka transforms about to getting a larger matter than just the Kb then chemical compounds will be an acidic.
In the event the Kb transforms going to feel more substantial count than simply the new Ka then agents would be a base.
Give the Kb and you can share with perhaps the chemical compounds is an acid otherwise legs in the event it has a beneficial Ka out-of 2.4 * 10 -six .
Answer: Acid (Ka is bigger than Kb), Kb = ten -fourteen / 2.4 * 10 -6 = cuatro.17 * ten -nine
Give the Ka and you may tell if the chemical substances are an acidic otherwise ft when it keeps good Kb off step three.5 * 10 -cuatro .
Answer: Foot (Kb was larger than Ka), Ka = ten -14 / step 3.5 * ten -4 = dos.86 * 10 -eleven
Supply the Kb and you will tell whether the chemical is actually an acid otherwise ft if this have good Ka away from 4.step 3 * 10 -9 .
Answer: Ft (Kb is actually bigger than Ka), Kb = 10 -fourteen / cuatro.3 * ten -nine = dos.thirty two * 10 -six
Allow the Ka and you will give whether or not the toxins is actually an acid or legs whether it keeps good Kb of 8.nine * ten -eleven .
Answer: Acid (Ka try larger than Kb), Ka = 10 -14 / 8.9 * 10 -11 = step one.several * 10 -4
Allow the Kb and share with whether or not the chemical are an acid or legs whether or not it provides a beneficial Ka off eight.dos * ten -9 .
Answer: Legs (Kb is actually bigger than Ka), Kb = 10 -fourteen / seven.2 * ten -9 = step one.38 * 10 -6
Give the Ka and you can give if the chemical compounds are an acid or ft whether or not it keeps a great Kb out-of 4.dos * ten -12 .
Answer: Acid (Ka is actually larger than Kb), Ka = 10 -fourteen / cuatro.dos * ten -11 = 2.38 * 10 -cuatro
Supply the Kb and you will share with whether the agents are an acid or base whether it has an excellent Ka regarding 3.cuatro * ten -step three .
Upcoming what can be the Ka
Answer: Acidic (Ka are bigger than Kb), Kb = ten -14 / step three.cuatro * 10 -step three = dos.94 * 10 -several
Give the Ka and give if the toxins is actually an acidic otherwise base if it keeps a Kb of five.six * 10 -eight .
Answer: Feet (Kb was bigger than Ka), Ka = ten -14 / 5.six * 10 -eight = 1.78 * ten -8