Physical meaning of pka which of the following aqueous solutions has the lowest ph: 0.1 m hcl; 0.1 m acetic acid (pka = 4.86); 0.1 m formic acid (pka = 3.75)?

The solution with the lowest pH is 0.1 M HCl.

Explanation:

Since the three solutions have the same concentration (0,1M) it is only necessary to look at the pKa of each solution.

Also, knowing that a higher pKa means a lower Ka, because pKa = -Log (Ka). Thus, a lower Ka means a lower concentration of protons with a higher pH ( pH = -Log [H+].

The HCl doesn't have a pKa because is a strong acid that dissociates completely. Therefore, this solution produces a lower pH. Looking at the pKa of acetic acid and formic acid solutions, the second with the lowest pH is the formic acid solutions and the higher pH is for the acetic acid solution.

2b2t

explanation:

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answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.