Stoichiometry Flashcards
Stoichiometry
2mol C8 H18: 25mol 02
Ratio
The study of the numerical relationship between chemical quantities In a chemical reaction
Reaction stoichiometry
What do the coefficients in a chemical reaction specify
1CH8 —> 1 mole of CH8
The coefficients in a chemical reaction specify the relative amounts in loses of each of the substance involved in the reactions
What is a limiting reactant?
Least amount of product aka the limiting reagent
This will run out first
What is a theoretical yield?
Amount of product that can be made in a chemical reaction based on the amount of limiting reactant
How many you can get based on the limiting reactant
The actual amount of product made in a chemical reaction
(Assume that while making pizzas we burn a pizza, drop one on the floor, or other uncontrollable events happen so that we make only 2 pizzas)
Actual yield
We can determine the efficiency of making pizzas by calculating the percentage of the maximum number of pizzas we actually make.
In chemical reactions we call this the_____
Percent yield
actual yield ( 2 pizzas)/ 3 pizzas ( theoretical yield) x 100 = % yield
Reactants not completely consumed are called
Excess reactants
Calculating the limiting reactant
20-23
Calculating limiting reactant, theoretical yield, and percent yield from reactant masses:
What unit do we normally measure reactant quantities in?
To find limiting reactant and theoretical yield, we must first convert____ to____
Grams
Grams to moles
Solution concentration and solution stoichiometry:
What is solvent?
What is solute
A solution in which water is the solvent____
The majority of the solution
The minority component
Aqueous solution
To describe solutions accurately we quantify the amount of solute relative to solvent or
Concentration of solution
Two different descriptions of solutions match them
Solutions that have a small amount of solute compared to solvents
Solutions have a large amount of solute compared to solvents
Dilute solutions
Concentrated
A common way to express solution concentration is (molarity) (M)
Molarity is the amount of solute ( in moles)
Divided by the volume of solution ( in liters)
M= amount of solute (in mol)/ volume of solution (in L)
Solution Dilution:
Solutions are stored as concentrated___
Stock solutions
How do you make solutions of lower concentrations to stock solutions
More solvent is added
( the amount of solute doesn’t change, just the volume of solution)
Moles solution in solution 1 = moles solute in solution 2
The concentrations and volumes of the stock and new solutions are inversely proportional
M1x V1= M2 x V2
Molarity relates the ______ of a solute to the _____ of the solution
It can be used to convert between amount of ______ or _____ in a chemical solution
( the general conceptual plan for these kinds of calculations begins with the volume of a reactant or product
Moles
Liters
Reactants
Products
What happens when a solute dissolves?
There are_____forces between the _____ solute particles holding them together
There are also attractive forces between the ______molecules
Attractive
Solute
Solvent
When we mix the solute with solvent what happens
There are attractive forces between the solute particles and the solvent molecules
What will happen if there is a strong attraction between a solute and solvent?
If strong enough the solute will dissolve
Charge Distribution in a water molecule:
There is an ______ distribution of electrons within a water molecule which causes the oxygen side of the molecule to have a ________ charge and the hydrogen side to have a partial _______ charge
Uneven
Partial negative
Positive
Solute and Solvent interactions in a sodium chloride solution:
When a sodium chloride is put into water, the attraction of Na+ and Cl- ions to water molecules competes with the attraction among the oppositely charged ions themselves. Describe what that would look like.
Na+ Cl-
The partial negative of the O would attract with the Na+ and the partial positives of the H would attract to the Cl- ( Solvent- Solute interactions)
And the Na+ would attract with the Cl- ( solute- solute interactions)
Dissolution of Ionic compounds:
Summary- each ion is attracted to the surrounding water molecules and pulled off and away from the crystal.
When it enters the solution the ion is surrounded by water molecules insulating it from other ions. But what is the final result?
The result is a solution with free moving charged particleS able to conduct electricity
Like ants swarming around a piece of food they carry part of the lattice crystal apart
Electrolyte and Nonelectrolyte solutions:
what is formed when materials dissolve in water to form a solution containing ions ?
They will conduct electricity ( electrolytes)