Thermoplastics and thermosetting polymers Examples include: polyethylene (PS) and polyvinyl choline (PVC). Common thermoplastics range from 20,000 to 50,000 amu, while thermosets are assumed to have infinite molecular weight.
white phosphorus is used in flares and explosives, so may be important in warfare, etc. Red phosphorus is used in matches (side of matches) and in fertilizers which are essential to growing plants. I don't know if that is economically important, but there are many ways that phosphorus benifit the economy. One downside on the economy is that phosphorus is one of the main ingredients in meth, which of course causes trouble for the economy ( law enforcement, medical, etc. )
Answer:
185.05 g.
Explanation
Firstly, It is considered as a stichiometry problem.
From the balanced equation: 2LiCl → 2Li + Cl₂
It is clear that the stichiometry shows that 2.0 moles of LiCl is decomposed to give 2.0 moles of Li metal and 1.0 moles of Cl₂, which means that the molar ratio of LiCl : Li is (1.0 : 1.0) ratio.
We must convert the grams of Li metal (30.3 g) to moles (n = mass/atomic mass), atomic mass of Li = 6.941 g/mole.
n = (30.3 g) / (6.941 g/mole) = 4.365 moles.
Now, we can get the number of moles of LiCl that is needed to produce 4.365 moles of Li metal.
Using cross multiplication:
2.0 moles of LiCl → 2.0 moles of Li, from the stichiometry of the balanced equation.
??? moles of LiCl → 4.365 moles of Li.
The number of moles of LiCl that will produce 4.365 moles of Li (30.3 g) is (2.0 x 4.365 / 2.0) = 4.365 moles.
Finally, we should convert the number of moles of LiCl into grams (n = mass/molar mass).
Molar mass of LiCl = 42.394 g/mole.
mass = n x molar mass = (4.365 x 42.394) = 185.05 g.
Answer:
The solutions should be added in this order NaCl > Na2SO4 > Na2S
Explanation:
Silver is insoluble as a chloride, so the silver ions get precipitated on addition of chloride ion as silver chloride. This means Ag+ would be removed the first.
So we will add NaCl in the first step.
The following reaction will occur.
Ag+ + Cl- → AgCl(s)
Both, Pb2 and Ni are soluble as chlorides. (lead chloride is soluble as a hot solution but will ppt when colder).
When we add Na2SO4, Pb2+ will get precipitated (because it's insoluble) as PbSO4 and Ni will remain soluble as NiSO4 is soluble in water.
The reaction that will occur is:
Pb^2+ + SO4^2- → PbSO4(s)
Nickel is insoluble as a sulfide. So when we will add Na2S, nickel will be precipitated as sulfide and be able to separate and be collected.
The solutions should be added in this order NaCl > Na2SO4 > Na2S
