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
This name is phosphine flammable , toxic gas colourless
...it's formula is PH3
Answer:
When the two atoms move towards each other a compound is formed by sharing electron pairs supplied by each of the atoms to enable them have the stable 8 (octet) valency electrons in their outermost shell
Explanation:
The electronic configuration of the given element can be written as follows;
1s²2s²2p⁴
The given electronic configuration is equivalent to that of oxygen, therefore, we have;
The number of electrons in the valence shell = 2 + 4 = 6 electrons
Therefore, each atom requires 2 electrons to complete its 8 (octet) electrons in the outermost shell
When the two atoms move towards each other, they react and combine to form a compound by sharing 4 electrons, 2 from each atom, such that each atom can have an extra 2 electrons in its outermost orbit in the newly formed compound and the stable octet configuration is attained by each of the atoms in the newly formed compound.
Answer: The average atomic mass of X is 16.53
Explanation:
Mass of isotope X-19 = 2.282
% abundance of isotope X-19 = 12.01% = 
Mass of isotope X-21 = 18.48
% abundance of isotope X-21 = (100-12.01)% = 
Formula used for average atomic mass of an element :
![A=\sum[(2.282\times 0.1201)+(18.48\times 0.8799)]](https://tex.z-dn.net/?f=A%3D%5Csum%5B%282.282%5Ctimes%200.1201%29%2B%2818.48%5Ctimes%200.8799%29%5D)
Therefore, the average atomic mass of X is 16.53
Answer:
10.2 g
Explanation:
<em>A mixture of ethyl alcohol (molecular mass = 46.1 u) and water (molecular mass = 18.0 u) contains one mole of molecules.</em>
<em />
The mixture contains 20.0 g of ethyl alcohol. The molar mass of ethyl alcohol is 46.1 g/mol. The moles of ethyl alcohol are:
20.0 g × (1 mol / 46.1 g) = 0.434 mol
The sum of the moles of ethyl alcohol and the moles of water is 1 mole.
n(ethyl alcohol) + n(water) = 1 mol
n(water) = 1 mol - n(ethyl alcohol) = 1 mol - 0.434 mol = 0.566 mol
The molar mass of water is 18.0 g/mol. The mass of water is:
0.566 mol × (18.0 g/mol) = 10.2 g
