You have to use Avogadro's number (6.02x10^23 molecules/mole) to find the number of moles each reactant starts off with.
moles of Fe and O₂:
12 atoms/(6.02x10^23 atoms/mole)=1.99x10^-23 mol Fe
6 molecules/(6.02x10^23 molecules/mole)=9.967x10^-24 mol <span>O₂
</span>Then you find the limiting reagent by finding how much product each given amount of reactant can make. Which ever one produces the least amount of product is the limiting reagent.
amount of Fe₂O₃ produced:
<span>(1.99x10^-23 mol Fe)x(2mol/4mol)= 9.967x10^-24mol Fe</span>₂O₃<span>
</span>(9.967x10^-24 mol O₂)x(2mol/3mol)= 6.645x10^-24 mol Fe₂O₃<span>
</span>since oxygen produces the leas amount of product, oxygen is the limiting reagent. since we know that oxygen is the limiting reagent we can use the amount of product formed with oxygen to find the amount of iron used.
6.645x10^-24 mol Fe₂O₃x(4mol/2mol)=1.329x10^-23 mol Fe consumed
<span> find the amount left over by subtracting the original amount of Fe by the amount consumed in the reaction.
</span>1.993x10^-23-1.329x10^-23= 6.645x10^-23mol Fe left
find the number of atoms by multiplying that by Avogadro's number.
<span>(6.645x10^-23mol)x(6.02x10^23 atoms/mol)=4 atoms
</span>therefore 4 atoms of Fe will be left over after the reaction happens.
I hope this helps.
The two strands of a DNA molecule must be separated
Answer:
The answer to your question is below
Explanation:
2.- 6
3.- Carbon
4.- These electrons can be share to obtain stability.
5.- Protons, electrons
6.- electron cloud
7.- I and III
8.- 1
9.- 8A
10.- 4
11.- F
12.- F
13.- F
14.- T
15.- T
16.- T
17.- T
18.- T (I can not read the question but I think is true)
Answer:
<span>Formula New Combination Predicted Formula
</span>
NaCl potassium + chlorine KCl
AlCl₃ aluminum + fluorine AlF₃
CO₂ tin + oxygen SnO₂
MgCl₂ calcium + bromine CaBr₂
HCl cesium + iodine CsI
<span>
CCl₄ silicon + bromine SiBr₄</span>
Explanation:
1) The question is incomplete. The first part is missing.
This is the first part of the question.
<span>Applying
the principle that the elements of a particular column in the Periodic
Table share the same chemical properties, complete the following chart.
The first one has been done for you.
</span>
2) This is the given chart:
<span>Formula New Combination Predicted Formula
</span>
Cu₂O silver + oxygen Ag₂O ← this is the example.
NaCl potassium + chlorine
<span>
AlCl₃ aluminum + fluorine </span>
CO₂ tin + oxygen
<span>
MgCl₂ calcium + bromine </span>
<span>
HCl cesium + iodine </span>
<span>
CCl₄ silicon + bromine
</span>
3) This is how you find the new formula to complete the chart.
i) NaCl potassium + chlorine
Since potassium is in the same group of sodium, you predict that in the new formula Na is replaced by K giving KCl.
ii) AlCl₃ aluminum + fluorine
Since fluorine is in the same group that Al, then you predict that in the new formula Cl is replaced by F leading to AlF₃
iii) CO₂ tin + oxygen
Since tin is in the same group that C, you predict that in the new formula C is replaced by Sn leading to SnO₂
iv) MgCl₂ calcium + bromine
Since calcium is in the same group that Mg, and bromine is in the same group that Cl, you predict thea in the new formula calcium replaces Mg and bromine replaces Cl, leading to CaBr₂
v) HCl cesium + iodine
Since H is in the same column that cesium and Cl is in the same colum that iodine, you predict that in the new formula Cs replaces H and I replaces Cl leading to: CsI
<span>
vi) CCl₄ silicon + bromine
</span>
Since silicon is in the same column that C and bromine is in the same column that Cl, you predict that in the new formula Si replaces C and Br replaces Cl, leading to SiBr₄
