Answer:
a change of environment
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
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]
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