Answer : The mass of 
required is 18.238 grams.
Explanation : Given,
Mass of 
= 83.10 g
Molar mass of = 146 g/mole
Molar mass of = 256.52 g/mole
The balanced chemical reaction is,
First we have to determine the moles of .
Now we have to determine the moles of .
From the balanced chemical reaction we conclude that,
As, 8 moles of produced from 1 mole of
So, 0.569 moles of produced from 
mole of
Now we have to determine the mass of .
Therefore, the mass of required is 18.238 grams.
Answer:
4552 mL
Explanation:
From the question given above, the following data were obtained:
Volume of stock solution (V₁) = 55 mL
Molarity of stock solution (M₁) = 12 M
Molarity of diluted solution (M₂) = 0.145 M
Volume of diluted solution (V₂) =?
The volume of the diluted solution can be obtained by using the dilution formula as illustrated below:
M₁V₁ = M₂V₂
12 × 55 = 0.145 × V₂
660 = 0.145 × V₂
Divide both side by 0.145
V₂ = 660 / 0.145
V₂ ≈ 4552 mL
Thus, the volume of the diluted solution is 4552 mL
The Great Oxidation Event (GOE), sometimes also called the Great Oxygenation Event, Oxygen Catastrophe, Oxygen Crisis, Oxygen Holocaust,[2] or Oxygen Revolution, was a time period when the Earth's atmosphere and the shallow ocean first experienced a rise in oxygen, approximately 2.4 billion years ago (2.4 Ga) to 2.1–2.0 Ga during the Paleoproterozoic era.[3] Geological, isotopic, and chemical evidence suggests that biologically produced molecular oxygen (dioxygen, O2) started to accumulate in Earth's atmosphere and changed Earth's atmosphere from a weakly reducing atmosphere to an oxidizing atmosphere,[4] causing many existing species on Earth to die out.[5] The cyanobacteria producing the oxygen caused the event which enabled the subsequent development of multicellular forms.
Equation: 2K + S --> K2S
Chemical formula: K2S
