Answer:
70%of 2000 = 1400
2000 tonnes of hematite contains 1400 tonnes iron oxide .
1400 tonnes of fe2O3
fe2O3 have molar mass 159.69
calculate moles = given mass/molar mass
moles = 1400000000/159.69
moles = 8766986
one mole contains = 112 g of fe
so 8766986 moles will contain = 112×8766986
= 981,902,432 grams of ferrous
which is nothing but equal to 981.90 tonnes of iron!!
<u>Answer:</u> The potential of electrode is -0.79 V
<u>Explanation:</u>
When zinc is dipped in zinc sulfate solution, the electrode formed is 
Reduction reaction follows: 
To calculate the potential of electrode, we use the equation given by Nernst equation:
![E_{(Zn^{2+}/Zn)}=E^o_{(Zn^{2+}/Zn)}-\frac{0.059}{n}\log \frac{[Zn]}{[Zn^{2+}]}](https://tex.z-dn.net/?f=E_%7B%28Zn%5E%7B2%2B%7D%2FZn%29%7D%3DE%5Eo_%7B%28Zn%5E%7B2%2B%7D%2FZn%29%7D-%5Cfrac%7B0.059%7D%7Bn%7D%5Clog%20%5Cfrac%7B%5BZn%5D%7D%7B%5BZn%5E%7B2%2B%7D%5D%7D)
where,
= electrode potential of the cell = ?V
= standard electrode potential of the cell = -0.76 V
n = number of electrons exchanged = 2
![[Zn]=1M](https://tex.z-dn.net/?f=%5BZn%5D%3D1M)
(concentration of pure solids are taken as 1)
![[Zn^{2+}]=0.1M](https://tex.z-dn.net/?f=%5BZn%5E%7B2%2B%7D%5D%3D0.1M)
Putting values in above equation, we get:
Hence, the potential of electrode is -0.79 V
Compounds in order of increasing acidity will be written as d<c<b<a.
<h3>What is acidity?</h3>
The quantity of hydroxyl ions that a basic molecule may create in an aqueous solution is what is known as the acidity of bases. The quantity of hydronium ions that a substance may create in an aqueous solution determines how basic an acid is.
a, b are more acidic than c and d because of OH group attached to sp2 hybridised carbon which provide resonance stability for conjugate base
in c f has -I effect which increases acidity in a, NO2 has -m effect which increases acidity so increasing order is d<c<b<a
that is cyclohexanol < 2,4-difluorocyclohexanol < phenol < 2,4-dinitrophenol
to learn more about acidity go to -
brainly.com/question/19584961
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