Answer:
A.
Explanation:
The potential energy of the roller coaster increases as the coaster goes up a hill and can be converted to kinetic energy.
Answer:
18.9 x 10¹³ grams of Bauxite Ore
Explanation:
Al₂O₃ = 50% of Bauxite Ore
Al₂O₃ = 0.5 (Bauxite Ore)--------------------------------------- (1)
Overall reaction:
2Al₂O₃ + 3C → 4Al + 3CO₂--------------------------------------- (2)
[ Al= 27 , O=16, C=12]
From (2), 2 moles of Aluminium oxide (Al₂O₃) gives 4 moles of Aluminium
In terms of grams, we can say:
Al₂O₃ = [2(27) +3(16)]
= 54 +48
=102grams
2 moles of Al₂O₃ = 2 x102grams
=204grams
4 moles of Al = 4 x 27
=108 grams
So from (2):
204 grams of Al₂O₃ = 108 grams of Aluminium
x grams of Al₂O₃ = 5.0 x 10¹³grams of Aluminium
Calculating for x:
x = (204 x 5.0 x 10¹³)/ 108
= 9.44 x 10¹³ grams
So 9.44 x 10¹³ grams of pure bauxite (Bauxite) is required.
However the to calculate the quantity of raw bauxite, we use (1):
Bauxite ore = Pure Bauxite/0.5
= 9.44 x 10¹³ grams/0.5
= 18.88 x 10¹³ grams
≈ 18.9 x 10¹³ grams
In every 100g of that compund there is 50.84 g of C, 8.53 g H and (100-59.37) g = 40.63 g of O.
Step 1: Convert each element's mass in moles. To do that we need to divide each element's mass by their respective molar mass.
For Carbon.
For Hydrogen.
For Oxygen.
Step 2: Divide each of the numbers by the smallest number.
For Carbon.
For Hydrogen.
For Oxygen.
Step 3: So the empirical formula will be.
But using decimal will be messy. So we multiply the numbers by 3. The right empirical formula will be.
