# Solveing Stoichiometry

## Reaction

Stoichiometry: Chemistry for Massive Creatures - Crash Course Chemistry #6

## Type of Reaction

Single Replacement- Because there is a single metal (Pb), plus a compound with a metal (Ag) and a polyatomic (NO3).

## Balanced Equation

1Pb+2Ag(NO3)---> 1Pb(NO3)2+2Ag

## Molar Mass of Reactants and Product

To find the Molar Mass of the reactants and the product, you look on the Periodic Table.

Using that find the mass of each.

Ex.

207.2+(169.872)--->269.204+107.868

Pb + Ag(NO3)-------> Pb(NO3) + Ag

## Mole to Mole Conversions

To find the Mole to Mole conversion you must first have a starting mole of "Mole A" (the amount of moles of reactant 1- given in a problem). Then you write the second reactant "Mole B" across the table. Then under that you put "Mole A" again. On the last two you use the Coefficients. Then you multiply across the top and divide by the bottom.

When i did this conversion through the table my "Mole A" (given from question) was 2.11 moles of Pb. My "Mole B" (Ag(NO3)) had the Coefficient of 2. And my second "Mole A" had a Coefficient of 1. Multiplying by the top then Dividing by the bottom i got

4.22 moles of (Ag(NO3)).

## Video Example of Mole to Mole and Mass to Mass

Mole-to-mole and Mass-to-mass Conversions

## Mass to Mass Conversions

To find the mass to mass conversion of my reaction i plug in the given to the beginning of the table, the molar mass to the "Grams A". Plug in Coefficients to "Moles A & B". The plug in the molar mass of reactant B to "Grams B". Then work it out.Table located below.

In my Reaction

12.1g Pb- Grams A

207.2g Pb- Molar mass of Gram A

2- Coefficient of mole B

1- Coefficient of mole A

169.872g Ag(NO3)- Grams B

I multiplied across the top then divided by the bottom and came out with 19.8g of (Ag(NO3))

## Limiting Reactant

The limiting reactant is the reactant that runs out the fastest in the reaction. For example, when we were making smores the first thing to run out was the Chocolate, so that was the limiting reactant for that problem. Its the limiting reactant because it limits the reaction to the amount of the limiting reactant you have.

In my case Ag(NO3) was my Limiting Reactant because there was the least amount of it in the reaction.

## Excess Reactant

The excess reactant is whatever is left over. So in the smores lab the crackers and the marshmallows were the excess reactants because they are left over, hence excess.

In my reaction Pb is my excess reactant because i have it left over.

## Theoretical Yield

The calculated amount of the reaction you can make, assuming everything goes as planned. Find by putting both the reactants through the mass to mass conversion table.

The Reaction that comes out the least is the theoretical, because there is less and it limits the reaction to that amount.

In my equation the theoretical yield is (7.18 Ag) compared to (12.806 Pb), Ag is the theoretical yield because it is the smallest.

## Percent yield

Is the percent of the product actually made compared to the theoretical yield.

Formula-

(Actual) / (Theoretical) x (100)= (Percent Yield)

My Reaction-

7.81g of Ag- Theoretical

9.02g of Ag- Actual

9.02 / 7.81 x 100= (115.4%)

115.4% is my Percent Yield

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