2 answers:
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Explanation:
According to the Henderson-Hasselbalch equation, the relation between pH and is as follows.
pH =
where, pH = 7.4 and = 7.21
As here, we can use the nearest to the desired pH.
So, 7.4 = 7.21 +
0.19 =
= 1.55
1 mM phosphate buffer means +
= 1 mM
Therefore, the two equations will be as follows.
= 1.55 ............. (1)
+
= 1 mM ........... (2)
Now, putting the value of from equation (1) into equation (2) as follows.
1.55 = 1 mM
2.55 = 1 mM
= 0.392 mM
Putting the value of in equation (1) we get the following.
0.392 mM + = 1 mM
= (1 - 0.392) mM
= 0.608 mM
Thus, we can conclude that concentration of the acid must be 0.608 mM.
A saturated solution is one in which no more solute is able to dissolve in a given solvent at a particular temperature. Some amount of the solute is left undissolved in the solution.
Unsaturated solution has solute in lower proportions than required to form a saturated solution.
Supersaturated solution has solute in amounts greater than a saturated solution.
We can take the help of solubility curve in order to find out the amount of a salt required to prepare a saturated solution of that salt at a particular temperature.
The solubility of KI at 10 is 136 g/ 100 mL water
The solubility of at
is 21 g/100 mL water.
The solubility of at
is 80 g/100 mL water.
The solubility of NaCl at is 38 g/ 100 mL water.
So the correct answer will be KI, as it would need 136 g KI / 100 mL water to form a saturated solution at .So, if we have 80g KI/ 100mL water it would be an unsaturated solution.