The Ionic Product of Water, \({K_{\rm{w}}}\), is the equilibrium constant for the reaction in which water undergoes an acid-base reaction with itself.
\({K_{\rm{w}}} = \left[ {{H_3}{O^ + }_{(aq)}} \right]\left[ {O{H^ - }_{(aq)}} \right] = {10^{ - 14}}at25{}^oC\)
The value of Kw increases almost 75 times when temperature is increased from 0°C to 100°C .
According to the above equation, what type of behavior is shown by water?
Explanation
As shown in the above equation, Water is donating proton and hydroxyl ion at the same time. So, water is behaving as an acid as well as base.
Alternative explanation: Producing both the + and – for acid and base.
Battery companies make impressive claims about how long their batteries will last. A student decided to test the running time of different batteries to determine which battery lasts the longest. The student tested 6 different batteries, 4 brand name and 2 generic, using flashlights. The results show that the battery referred to as Name Brand A lasted the longest, with 101 hours of runtime:
Flashlight | Battery | Runtime in hours |
Gearlight Super Light | Name Brand A | 101 |
SureFire | Name Brand B | 99 |
Maglight | Name Brand C | 80 |
Bright Star | Name Brand D | 75 |
SureFire | Generic A | 30 |
Bright Star | Generic B | 29 |
It could be argued that this experiment was not set up using proper experimental protocol. What would need to change in the experiment for the results to be valid?