With the given components above, the chemical reaction required to solve the problem is <span>H2C2O4*2H2O + 2 NaOH = 4 H2O + Na2C2O<span>4 where 1 mole of diprotic acid needs 2 moles of NaOH to complete the reaction.In this case, given </span></span><span>0.4500 M NaoH and 0.02 L of it, the moles diprotic acid needed is 0.0045 moles. This is equivalent to 0.351 grams.</span>
RMM of magnesium oxide=24+16=40
40g=1mol
therefore 62.5g will have =62.5/40=1.5625 moles
1.5 litres contain 1.5625 mols
therefore 1 litre =1*1.5625/1.5=1.042M
Answer:
E. Evaporation to dryness
Explanation:
E. - Evaporation to dryness is the best method for the recovery of solid KNO3 from an aqueous solution of KNO3.
(KNO3 is very soluble, and will violently decompose if overheated.)
Paper chromatography is for separation of different weight molecules in solution.
B. Filtration won't work on a solution
C.Titration would contaminate the salt with something else and is used
to determine concentrations
D. Electrolysis would destroy the salt
The objects speed and direction of motion or change of its position
Answer:
7.08
Explanation:
To solve this problem we'll use the <em>Henderson-Hasselbach equation</em>:
- pH = pka + log
![\frac{[A^-]}{[HA]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
Where
is the ratio of [sodium formate]/[formic acid] and pka is equal to -log(Ka), meaning that:
- pka = -log (1.8x10⁻⁴) = 3.74
We<u> input the data</u>:
- 4.59 = 3.74 + log
![\frac{[A^-]}{[HA]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
And<u> solve for </u>
:
- 0.85 = log
![\frac{[A^-]}{[HA]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
=![\frac{[A^-]}{[HA]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
= 7.08