Answer:
The formula for the anhydrous compound that was part of the mixture called natron that was used by the Egyptians is Na2(CO3)10(H2O).
They use this compound for medicine, cookery, agriculture, in glass-making and to dehydrate egyptian mummies.
Compound of sodium carbonate and sodium bicarbonate was the name of the resulting hydrate that formed.
1. A 2. B 5. B this is all I know hope it helps
Answer:
Force of attraction = 35.96
N
Explanation:
Given: charge on anion = -2
Charge on cation = +2
Distance = 1 nm =
m
To calculate: Force of attraction.
Solution: The force of attraction is calculated by using equation,
---(1)
where, q represents the charge and the subscripts 1 and 2 represents cation and anion.
k = 
F = force of attraction
r = distance between ions.
Substituting all the values in the equation (1) the equation becomes

Force of attraction = 35.96
N
The given question is incomplete. The complete question is as follows.
Sodium sulfate is slowly added to a solution containing 0.0500 M
and 0.0390 M
. What will be the concentration of
(aq) when
begins to precipitate? What percentage of the
can be separated from the Ag(aq) by selective precipitation?
Explanation:
The given reaction is as follows.

= 0.0390 M
When
precipitates then expression for
will be as follows.
![K_{sp} = [Ag^{+}]^{2}[SO^{2-}_{4}]](https://tex.z-dn.net/?f=K_%7Bsp%7D%20%3D%20%5BAg%5E%7B%2B%7D%5D%5E%7B2%7D%5BSO%5E%7B2-%7D_%7B4%7D%5D)
![1.20 \times 10^{-5} = (0.0390)^{2} \times [SO^{2-}_{4}]](https://tex.z-dn.net/?f=1.20%20%5Ctimes%2010%5E%7B-5%7D%20%3D%20%280.0390%29%5E%7B2%7D%20%5Ctimes%20%5BSO%5E%7B2-%7D_%7B4%7D%5D)
= 0.00788 M
Now, equation for dissociation of calcium sulfate is as follows.

![K_{sp} = [Ca^{2+}][SO^{2-}_{4}]](https://tex.z-dn.net/?f=K_%7Bsp%7D%20%3D%20%5BCa%5E%7B2%2B%7D%5D%5BSO%5E%7B2-%7D_%7B4%7D%5D)
![4.93 \times 10^{-5} = [Ca^{2+}] \times 0.00788](https://tex.z-dn.net/?f=4.93%20%5Ctimes%2010%5E%7B-5%7D%20%3D%20%5BCa%5E%7B2%2B%7D%5D%20%5Ctimes%200.00788)
= 0.00625 M
Now, we will calculate the percentage of
remaining in the solution as follows.

= 12.5%
And, the percentage of
that can be separated is as follows.
100 - 12.5
= 87.5%
Thus, we can conclude that 87.5% will be the concentration of
when
begins to precipitate.
Answer:
chyba się zniszczy
Explanation:
ponieważ sie film prześwietli