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.
Answer:
Antibodies are types of proteins in the body that can prevent diseases. Once a vaccine is introduced into the bloodstream, it immediately causes the production of antibodies to occur by using T-cells and B lymphocytes, or at least, most vaccines work like that.
Explanation:
Question: Baking a Cake Without Flour.
Hypothesis: I think that when I remove the flour from the standard cake recipe, I'll end up with a flat but tasty cake.
Procedure: I baked two cakes during my experiment. For my control, I baked a cake following a normal recipe. I used the Double Fudge Cake recipe on page 292 of the Betty Crocker Cookbook. For my experimental cake, I followed the same recipe but left out the flour. I first obtained a 2-quart mixing bowl.
Results: My control cake, which I cooked for 25 minutes, measured 4 cm high. Eight out of ten tasters that I picked at random from the class found it to be an acceptable dessert. After 25 minutes of baking, my experimental cake was 1.5 cm high and all ten tasters refused to eat it because it was burnt to a crisp.
What did I learn?/Conclusion: Since the experimental cake burned, my results did not support my hypothesis. I think that the cake burned because it had less mass, but cooked for the same amount of time. I propose that the baking time be shortened in subsequent trials.
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I hope this helped :))
Answer:
The concentration of methyl isonitrile will become 15% of the initial value after 10.31 hrs.
Explanation:
As the data the rate constant is not given in this description, However from observing the complete question the rate constant is given as a rate constant of 5.11x10-5s-1 at 472k .
Now the ratio of two concentrations is given as
Here C/C_0 is the ratio of concentration which is given as 15% or 0.15.
k is the rate constant which is given as 
So time t is given as
So the concentration will become 15% of the initial value after 10.31 hrs.
Answer:
In 1827, Brown observed, using a microscope, that small particles ejected from pollen grains suspended in water executed a kind of continuous and jittery movement, this was named “Brownian motion”. ... This random movement of particles suspended in a fluid is now called after him.
Explanation:
HOPE this helps :)
