Am letting the picture doing the talk.
Citric acid , (COOH)CH2-C(OH)(COOH)-CH2(COOH) is a triprotic acid with three acidic protons. It can be represented as H3A
The equilibrium reaction are:
1) H3A -------- H2A- + H+ pKa1 = 3.14
2) H2A- --------- HA2- + H+ pKa2 = 4.76
3) HA2- -------- A3- + H+ pKa3 = 6.40
The given pH = 4.2 which is closest to pKa2. hence the two ions that will be present are: H2A- and HA2-
As per Henderson Hasselbach equation:
pH = pka + log [HA2-]/[H2A-]-----------(1)
[HA2-]/[H2A-] = 10^(pH-pKa) = 10^(4.2-4.76) = 0.275
i.e. [HA2-] = 0.275 [H2A-]-----------------(2)
It is given that: [HA2-] + [H2A-] = 50 mM ---------------(3)
substituting for HA2- IN eq(3) we get:
1.275 [H2A-] = 50 mM
[H2A-] = 50/1.275 = 39.22 mM
[HA2-] = 0.275(39.22) = 10.79 mM
Explanation:
The given data is as follows.
Mass of antimony = 19.75 g
Molar mass of Sb = 121.76 g/mol
Therefore, calculate number of moles of Sb as follows.
Moles of Sb =
=
= 0.162 mol
Mass of oxygen given is 6.5 g and molar mass of oxygen is 16 g/mol. Hence, moles of oxygen will be calculated as follows.
Moles of oxygen =
=
= 0.406 mol
Hence, ratio of moles of Sb and O will be as follows
Sb : O
1 : 2.5
We multiply both the ratio by 2 in order to get a whole number. Therefore, the ratio will be 2 : 5.
Thus, we can conclude that the empirical formula of the given oxide is .
Answer:
The answer is "False".
Explanation:
The given statement is false, which can be defined as follows:
- Molarity is focused on solution liters, which is focussed on kg of solvents when analyzing the property of solutions related to vapor temperature.
- Its pressure variations, quantities represented in molar concentration can be used.
- It is used when its meaning doesn't change with temperature changes. It can be calculated as the M1 x V1 = M2 x V2.