Concepts
In a chemical reaction, reactants that are not used up when the reaction is finished are called?
Excess reagents
Identify the limiting reagent in this equation:
Mg+O2→MgOMg+O2→MgO
Hint: Before a limiting reagent is identified, the reaction must be balanced.
Thus, two moles of Mg require only ONE mole of O2. Four moles of oxygen will remain unreacted. Therefore, oxygen is the excess reagent, and MgMg is the limiting reagent.
The amount of limiting reagent present in a reaction mixture is _____ than that of the excess reagent.
lower
What is a basic requirement for identifying the limiting reagent even if amounts of reactants are known.
Balancing the equation
What is the relathionship between Limiting Reagent and Excess Reagent?
A real reaction will always have a limiting reagent and an excess reagent since limiting is one in which it produces the least amount of product and an excess reactant is one in which it produces more of a product.
The reagent that is completely used up or reacted is called the?
Limiting reagent
When 12 moles of O2 reacts with 6 moles of C10H8, what is the limiting reactant?
1 C10H8 + 12 O2 --> 10 CO2 + 4 H2O
Oxygen
How much the excess reagent remains if 24.5 grams of CoO is reacted with 2.58 grams of O2?
4CoO+O2→2Co2O3
0.327 molesof CoO
0.0806molesofO2
Which type of calculations is requiered to determine excess and limiting reagents in a chemical reaction
Stoichiometry
The reactant that is not completely used up in a chemical reaction is called the:
excess reagent
Why is called a limiting reagent?
Because its quantity limits the amount of products formed
1 Mg + 2 HCl --> 1 MgCl2 + 1 H2
Identify the limiting reagent when 6.00 moles HCl combines with 5.00 moles Mg to form MgCl2.
HCl
N2+ 3 H2 ---> 2 NH3
Identify the limiting and excess reactants in the reaction shown.
H2 is limiting and N2 is excess
One way of finding the limiting reagent is by:
Calculating the amount of product that can be formed by each reactant
2 Al + 3 Cl2 ---> 2 AlCl3. If 2 moles of aluminum and 2 moles of chlorine are reacted, identify the limiting reactant.
Cl2