The highest electronegativity is in the elements in the top left corner of the periodic table, and the lowest in the bottom right corner. Therefore, traveling up or to the left across the periodic table will increase the electronegativity
Answer:
Coefficients are the numbers in front of the formulas.
The strength of an Arrhenius base determines percentage of ionization of base and the number of OH⁻ ions formed.
Strong base completely ionize in water and gives a lot of hydroxide ions (OH⁻), for example sodium
hydroxide: NaOH(aq) → Na⁺(aq)
+ OH⁻(aq).
Weak base partially ionize in water and gives a few hydroxide ions (OH⁻), for example ammonia: NH₃ + H₂O(l) ⇄ NH₄⁺(aq) + OH⁻(aq).
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.