The soulustion. turn cloudy due to the precipitation of Sulphur.
Answer:
Standardisation is used to determine the concentration of a volumetric solution in order to achieve accurate and reliable titration results






Answer:
Explanation:
From the correct question above:
The reaction can be represented as:

From the above reaction; the ICE table can be represented as:

I (mol/L) 0.086 0.28 0 0
C -4x -3x +2x +6x
E 0.086 - 4x 0.28 - 3x +2x +6x
At equilibrium;
The water vapor = 


![\text{equilibrium constant} ({k_c}) = \dfrac{ [N_2]^2 [H_2O]^6 }{ [[NH_3]^4] [O_2]^3 }](https://tex.z-dn.net/?f=%5Ctext%7Bequilibrium%20constant%7D%20%20%28%7Bk_c%7D%29%20%3D%20%20%5Cdfrac%7B%20%5BN_2%5D%5E2%20%5BH_2O%5D%5E6%20%7D%7B%20%5B%5BNH_3%5D%5E4%5D%20%5BO_2%5D%5E3%20%7D)

Replacing the value of x, we have:


<span> Au</span>₂(SeO₄)₃
O = -2 × 4 = -8
Se = + 6
So,
(+6 - 8) = -2
Means (SeO₄) contains -2 charge, Now multiply -2 by 3
-2 ₓ 3 = -6
Means,
Au₂ + (-6) = 0
Au₂ = +6
Or,
Au = 6 / 2
Au = +3
Result:
Au = +3
Se = +6
O = -2
Ni(CN)₂
Cyanide (CN⁻) contains -1 charge,
So,
N = -3
C = +2
Then,
Ni + (-1)₂ = 0
Ni - 2 = 0
Or,
Ni = +2
Result:
N = -3
C = +2
Ni = +2
Definitely Calcium Chloride.
All the others are covalent.