Answer:
The mass fraction of ferric oxide in the original sample :
Explanation:
Mass of the mixture = 3.110 g
Mass of 
Mass of 
After heating the mixture it allowed to react with hydrogen gas in which all the ferric oxide reacted to form metallic iron and water vapors where as aluminum oxide did not react.
Mass of mixture left after all the ferric oxide has reacted = 2.387 g
Mass of mixture left after all the ferric oxide has reacted = y
The mass fraction of ferric oxide in the original sample :
I am answering A question
Answer:
80 grams
Explanation:
number of moles=mass/molar mass .
5=x/16, x=16*5
x=80 grams
TLDR: the answer is C. 22,920 years.
Half-life describes the amount of time for a radioactive substance to decay to one-half of the original substance’s weight. So, if we had 100g of C-14, after 5,730 years, only 50g remain; after another 5,730 years, only 25g would remain, and so on.
In this problem, we are meant to assume that the original amount of C-14 was 64g, and that, through decay, it forms N-14. We can figure out how many half lives have passed by figuring out how much 4 is out of 64 by dividing 64 by two repeatedly. Each time, count a half life.
64 - 32 (1 HL) - 16 (2 HL) - 8 (3 HL) - 4 (4 HL)
In this problem, 4 half lives have passed. We can now multiply this by the time for one half life to find how many years have passed.
4 x 5,730 = 22,920 years
Approximately 22,920 years have passed since the drawing was created.
Answer:
Two
Explanation:
The law of conservation of mass states that in an isolated system the mass present is neither destroyed nor created by chemical changes or physical changes.
This tells us that the mass of reactants must be equal to the product mass.
If 1 atom of Zn react with one atoms of sulfur, the product will be 1 molecule of zinc sulfide according to the equation below
Zn(s) + S(s) ⇒ ZnS(s)
therefore two atoms each f zinc and sulfur will product two molecules of Zn sulfide
