Answer: The answer is D.
Explanation: The warm water will cause the sugar to dissolve quicker.
There is 1 mole of electrons = 96500C and Ca = 40
Ca2+ + 2e --->Ca
Base on the formula above it means that there are 2 moles of electrons to produce 1 mole of calcium.
96500C x 2 = 193000C
193000C electricity produce 40g Calcium
Coulombs = Amps x seconds (28.70A for 12 hours)
= 28.70A x 12 x 60 x 60 C
= 1 239 840 C
This amount of electricity will produce
=1239840 / 193000 x 40g Calcium
= 6.42 x 40 g Calcium
= 256.96 g
So there will be 256.96g of Calcium metal that will be produced in 12 hours.
Mass of Oxygen : 8 g
<h3>Further explanation</h3>
Given
48g of Magnesium
32g of Oxygen
Required
Mass of Oxygen
Solution
The ratio of Mg and O in MgO :
48 g : 32 g = 3 : 2
Total ratio = 3+2 = 5
So for 20 g MgO, mass of Oxygen :
=2/5 x 20 g
=8 g
Or
%mass O = 32/80 x 100%=40%
mass O in 20 g MgO =
40% x 20 g =8 g
