How does the Sun get energy?
Answer:
Nuclear fushion
Explanation:
The sun generates energy from a process called nuclear fusion. During nuclear fusion, the high pressure and temperature in the sun's core cause nuclei to separate from their electrons
The blue colour of the sky results from the scattering of sunlight by air molecules. Blue light has a frequency if about 7.5*10^14Hz
Calculate the energy of a mole of photon associated with this frequency
Answer: The energy of a mole of photon associated with this frequency is [tex]49.5\times 10^{-20}J[/tex]
Explanation:
The energy and frequency are related by :
[tex]E=N\times h\times \nu[/tex]
E = energy of photon
N = number of moles = 1
h = planks constant = [tex]6.6\times 10^{-34}Js[/tex]
[tex]\nu[/tex] = frequency = [tex]7.5\times 10^{14}Hz[/tex]
[tex]E=1\times 6.6\times 10^{-34}Js\times 7.5\times 10^{14}s^{-1}=49.5\times 10^{-20}J[/tex]
The energy of a mole of photon associated with this frequency is [tex]49.5\times 10^{-20}J[/tex]
A 3.6 g sample of iron (III) oxide reacts with sufficient aluminum to be entirely used up.
How much iron is produced?
Answer:
0.046 mol
Explanation:
Step 1: Write the balanced equation
Fe₂O₃ + 2 Al ⇒ 2 Fe + Al₂O₃
Step 2: Calculate the moles corresponding to 3.6 g of Fe₂O₃
The molar mass of Fe₂O₃ is 159.69 g/mol.
3.6 g × 1 mol/159.69 g = 0.023 mol
Step 3: Calculate the moles of Fe produced from 0.023 moles of Fe₂O₃
The molar ratio of Fe₂O₃ to Fe is 1:2.
0.023 mol Fe₂O₃ × 2 mol Fe/1 mol Fe₂O₃ = 0.046 mol Fe