Chapter 4 - Chemical Quantities And Aqueous Reactions Flashcards
The study of the numerical relationship between chemical quantities in a chemical reaction is called
Stoichiometry
The amounts of any other substance in a chemical reaction can be determined from
• Think of pizza example
Just one substance
If one reactant in used up before the others, it is called the
Limiting Reactant
Reactants not completely consumed are called
Excess Reactants
The amount of product that can be made from the limiting reactant is called the
Theoretical Yield
The actual amount of product made in a chemical reaction is called the
Actual Yield
Because of both controllable and uncontrollable factors, the actual yield of product will always be ___ than the theoretical yield.
Less than
We can determine the efficiency of making pizzas by calculating the percentage of maximum number of pizzas we actually make. In a chemical reaction we call this the
Percent Yield
What is the formula for the Percent Yield?
(Actual Yield/Theoretical Yield) x 100%
When table salt is mixed with water, it seems to disappear, or become a liquid - the mixture is
Homogenous
Homogenous mixtures are called
Solutions
The compound of the solution that changes state is called the
Solute
The component that keeps its state is called the
Solvent
If both components start in the same state, the major component is the
Solvent
Because solutions are mixtures, their composition
Can vary from one sample to another
To describe solutions accurately, we must describe
How much of each component is present
____ Solutions have a small amount of solute compared to solvent
Dilute
____ Solutions have a large amount is solute compared to solvent
Concentrated
The amount of solute in a given amount of solution
Concentration
Used to describe how many molecules of solute is in each liter of solution
Solution Concentration Molarity
What is the Formula for Molarity
Amount of solute (in moles)/Amount of Solution(in L)
What is the formula to find the new volume in a concentration?
(M1xV1)/M2 = V2
Because molarity relates to the moles of solute to the liters of solution, it can be used to convert between amount of reactants and/or products in a chemical reaction
Solution Stoichiometry
There are attractive forces between the ____ particles to hold them together.
Solute
There are attractive forces between the ____ molecules.
Solvent
When we mix the solute with the solvent, there are attractive forces between ____
The solute particles and the solvent molecules
If the attraction between solute and solvent are strong enough, The solute will ____
Dissolve
Materials that dissolve in water to form a solution that will conduct electricity are called
Electrolytes
Materials that dissolve in water to form a solution that will not conduct electricity are called
Nonelectrolytes
Ionic compounds are ____ because they dissociate into their ions when they dissolve
Electrolytes
Molecular compounds ____ when they dissolve in water
Generally don’t ionize
____ are molecular compounds that ionize when they dissolve in water
Acids
When acids ionize, they form
H+ cations and anions
Across that ionize virtually 100% are called
Strong acids
Acids that only ionize a small percentage are called
Weak acids
___ ___ are materials that dissolve complete as ions
Strong electrolytes
___ ___ are materials that dissolve mostly as molecules but partially as ions
Weak acids
When compounds contains a polyatomic ion dissolve,
The polyatomic ion stays together
When ionic compounds dissolve in water, the anions and cations
Separate from each other (dissociation)
Wenn strong acids dissolve in water, the molecule
Ionizes into H+ and anions
Compounds that dissolve in a solvent are said to be ____, where as those that do not are said to be ____.
Soluble, insoluble
The best way to test whether compounds will dissolve is water is based on experiments and forming rules. This is called the
Empirical Method
Determine if the following are soluble in water
1) KOH
2) AgBr
3) CaCl2
4) Pb(NO3)2
5) PbSO4
1) soluble
2) insoluble
3) soluble
4) soluble
4) insoluble
___ ___ are reactions in which a solid forms when we mix two solutions
Precipitation reactions
An example of a precipitation reaction
Reactions between aqueous solutions of ionic compounds
Equations that describe the chemicals put into the water and the product molecules are called
Molecular Equations
Equations that describe the material’s structure when dissolved are called
Complete Ionic Equations
Ions that are both reactants and products are called
Spectator Ions
An ionic equation in which the spectator ions are removed is called a
Net Ionic Equation
Acid-Base Reactions
A reaction in which acid and base neutralize each other’s properties
What is another name for the Acid-Base reaction?
Neutralization Reactions
Based dissociate in water to
Form OH ions
In the reaction of an acid with a base, the __ from the acid combines with the __ from the base to make water
H+, OH
The ____ from the base combines with the ____ from the acid to make the salt
Cation, Anion
When a solution’s concentration is determined by reacting it with another material and using stoichiometry
Titration
In the titration, the unknown solution is added to a known amount of another reactant until the reaction is just completed. At this point, called the ____, the reactant are in their stoichiometric ratio
Endpoint
The unknown solution is added slowly from an instrument called a
Burette
Because both the reactant and and product solution in acid-base titrations are colorless, a chemical is added that
Changes color when the solution undergoes large changes in acidity/alkalinity
The chemical used in an acid-base titrations is called an
Indicator
What is the equivalence point?
At the endpoint of an acid-base titration, he number of moles of H+ duals the number of moles of OH
The ___ is the base solution in the burette
Titrant
Some reactions from a gas directly from the ion exchange, others from a gas by the decomposition of one of the ion exchange products into a gas and water
Gas-Evolving Reaction
Oxidation-Reduction Reactions
Involve transferring electrons from one atom to another
Reactions where electrons are transferred from one atom to another are
Redox Reactions
Atoms that lose electricians are being
Oxidized
Atoms that gain electrons are being
Reduced
Chemists assign a number to each element in a reaction called an ____ state that allows them to determine the electron flow in the reaction
Oxidation
What is the difference between ion charges and oxidation states?
Ion charges are real, measurable numbers. Oxidation states are imaginary charges assigned based on a set of rules.
___ occurs when an atom’s oxidation state increases during a reaction
Oxidation
____ occurs when an atom’s oxidation state decreases during a reaction
Reduction
Oxidation and reduction must occur
Simultaneously
The reactant that reduces an element in another reactant is called the
Reducing Agent
The reactant that oxidizes an element in another reactant is called the
Oxidizing Agent
