Answer:
The time required for the coating is 105 s
Explanation:
Zinc undergoes reduction reaction and absorbs two (2) electron ions.
The expression for the mass change at electrode 
is given as :
where;
M = molar mass
Z = ions charge at electrodes
F = Faraday's constant
I = current
A = area
t = time
also; = 
; replacing that into above equation; we have:
---- equation (1)
where;
A = area
d = thickness
= density
From the above equation (1); The time required for coating can be calculated as;
![[ \frac{20 cm^2 *0.0025 cm*7.13g/cm^3}{65.38g/mol}*2 \frac{moles\ of \ electrons}{mole \ of \ Zn} * 9.65*10^4 \frac{C}{mole \ of \ electrons } ] = (20 A) t](https://tex.z-dn.net/?f=%5B%20%5Cfrac%7B20%20cm%5E2%20%2A0.0025%20cm%2A7.13g%2Fcm%5E3%7D%7B65.38g%2Fmol%7D%2A2%20%5Cfrac%7Bmoles%5C%20of%20%5C%20electrons%7D%7Bmole%20%5C%20of%20%5C%20Zn%7D%20%2A%209.65%2A10%5E4%20%5Cfrac%7BC%7D%7Bmole%20%5C%20of%20%5C%20electrons%20%7D%20%20%5D%20%3D%20%2820%20A%29%20t)
= 105 s
Answer:
d , before the molten rock becomes lava, it is first magma, and most people know that lava is ejected from volcanoes
Answer ;
-An element is a substance containing only one type of atom, for example; H2 or 02 (consisting of atoms that all have the same number of protons).
-Microscopic, single atom of that element
-Macroscopic, sample of that element large enough to weigh on a balance
- A substance that cannot be broken down chemically; e.g; sodium metal,
Explanation;
-An element is a substance whose atoms all have the same number of protons: another way of saying this is that all of a particular element's atoms have the same atomic number. Elements are chemically the simplest substances and hence cannot be broken down using chemical reactions.
-An element is uniquely determined by the number of protons in the nuclei of its atoms.
Answer:
the double bond between c and o is shorter and weaker
Explanation:
this is because the bond between c and o involves unequal sharing of electrons whole c and c involves hybridization sp2 of orbitals and also catenation phenomenon in which carbon could form long chain with it's other carbon
Answer:
Reactions 1, 3 and 5
Explanation:
First thing's first, let's ensure that all the reactions given are balanced. This is given as;
CO(g) + 1/2 O2(g )→ CO2(g)
Li(s) + 1/2 F2(l) → LiF(s)
C(s) + O2(g) → CO2(g)
CaCO3(g) → CaO + CO2(g)
2Li(s) + F2(g) → 2LiF(s)
For the condition to be valid;
- There is by convention 1 mol of product made. This means we eliminate reactions with more than one mole of compound formed. This eliminates reaction 5.
- The lements haveto be in their state at room temperature. Fluorine is a gas, not a liquid, at room temperature ans pressure, so 2 is not a correct answer.
This leaves us with reactions 1, 3 and 5 as the correct reactions that satisify the condition.
