Answer:
No, 22.09% is not a valid measurement
Explanation:
Precision has to do with how close a given set of measured values are to each other. It is quite different from accuracy. Accuracy refers to how close a given set of values is to the true value. A given set of values may be precise but not accurate and vice versa.
If we look at the values obtained; 22.09%, 22.15%, 22.18%, 22.23%, 22.25%, the value 22.09% is too far off the other values. This implies that it does not represent a valid measurement since it is not close to all the other values obtained.
Answer:
4 moles, 160 g
Explanation:
The formula for the calculation of moles is shown below:

For
:-
Mass of
= 196 g
Molar mass of
= 98 g/mol
The formula for the calculation of moles is shown below:

Thus,


According to the given reaction:

1 mole of sulfuric acid reacts with 2 moles of NaOH
So,
2 moles of sulfuric acid reacts with 2*2 moles of NaOH
Moles of NaOH must react = 4 moles
Molar mass of NaOH = 40 g/mol
<u>Mass = Moles*molar mass =
= 160 g</u>
Answer:
Water is not a good solvent choice.
Explanation:
While water is good solvent because of its polotiry. Water is not good for the recrystallization process becuase being a good recystallization solvent means that a compound must dissolves easily when the solvent is warm, but that is less soluble at room temperature or when cooled in an ice bath. Water has the dissolves when warm part down. But for the cooled part which is the most important it can not do.
<u>Given:</u>
Concentration of HNO3 = 7.50 M
% dissociation of HNO3 = 33%
<u>To determine:</u>
The Ka of HNO3
<u>Explanation:</u>
Based on the given data
[H+] = [NO3-] = 33%[HNO3] = 0.33*7.50 = 2.48 M
The dissociation equilibrium is-
HNO3 ↔ H+ + NO3-
I 7.50 0 0
C -2.48 +2.48 +2.48
E 5.02 2.48 2.48
Ka = [H+][NO3-]/HNO3 = (2.48)²/5.02 = 1.23
Ans: Ka for HNO3 = 1.23