NET IONIC EQUATIONS
Ca(OH)2(s) -> Ca2+(aq) + 2OH-(aq)
What is stoichiometry the study of?
The relationships between the relative quantities of substances taking part in a chemical reaction.
What are the three important types of chemical reactions?
Acid-base reactions oxidation-reduction (redox) reactions, precipitation reactions
What are chemical reactions?
Processes that involve the breaking and/or formation of chemical bonds
What is a titration?
An experimental technique where a solution of known concentration (standard solution) is combined with a solution of unknown concentration to determine the amount of moles in the unknown.
What way can a physical process or chemical reaction can be represented?
Use chemical symbols to indicate reactants, products, and states of matter.
What is stoichiometry used for?
To predict the amounts of products produced or amounts of reactants required for reactions involving moles or grams, aqueous solutions, and gases.
When does a neutralization reaction occur?
When solutions of an acid and base are mixed
What is an instance in which physical processes do involve the breaking of chemical bonds?
Dissolution
What is a titrant and analyte?
(most often the solution of known concentration) is in the buret and the analyte is the unknown in the flask.
What can balanced equations be used to represent?
2H2 + O2 -> 2H2O
What would be present after the reaction?
4 mol H2
4 mol O2
4 mol O2- Excess reactant, 2 molecules O2 unreacted
4 mol H2 x 2 mol H2O / 2 mol H2 = 4 mol H2O
What is formed in a precipitation reaction?
An insoluble ionic compound from two aqueous solutions.
What are physical processes?
Only changes in intermolecular interactions, such as phase changes
When the amount of titrant added from the buret has completely reacted with all the analyte in the flask in stoichiometric ratios.
...Ca3(PO4)2(s) + ...H3PO4(l) -> ...Ca(H2PO4)2(s)
When the equation above is balanced and all the coefficients are reduced to lowest whole-number terms, what is the coefficient for H3PO4(l)?
4
What changes need to be made to increase the amount of products produced for Mg(s) + 2HC;(aq) -> MgCl2(aq) + H2(g) when 2.43g of Mg reacts with 100.0mL of 3.0M HCl at 273K and 1.0atm 2.24L of H2(g) are produced.
Increase the mass of Mg, increase the volume of HCl, increase the concentration of HCl
What dodes a Bronsted-Lowry acid-base reaction involve with protons?
A transfer of one or more protons (H+) from the acid to the base
Describe the changes in forces of attraction that occurs as H2O changes phase from a liquid to a vapor.
Hydrogen bonds between H2O molecules are broken.
What occurs at the end point of a titration?
The point at which the indicator changes color.
What are balanced molecular equations, complete ionic equations, and net ionic equations?
Balanced molecular equations show all species participating in a reaction. These equations indicate that mass is conserved. Complete ionic equations show ions in aqueous solution as separate charged particles. This type of equation can be used to easily identify spectator ions. Net ionic equations do not include spectator ions. A net ionic equation is useful to represent only the substances undergoing a chemical change.
Zn(s) + 2HCl(aq) -> ZnCl2(aq) + H2(g) the reaction occurs when 50.0mL of 1.00M HCl is added to 2.35g of Zn
When the reaction is complete at 273K and 1.0atm, what volume of H2(g) is produced?
Find the excess/limiting reactant, then convert into mol H2, and that into L of H2
0.560 L H2B) C2H3O2-(aq) + H3O+(aq) -> HC2H3O2(aq) +H2O(l)
C) Ca2+(aq) + SO42-(aq) -> CaSO4(s)
Which of the above reactions can be classified as an acid base reaction? As a redox reaction? as a precipitation reaction?
A) Redox
B) Acid-Base
C) Precipitation
A trip of Mg metal is placed into a crucible and is heated up.
Mass of crucible and Mg before heating: 35.6439g - Mass of crucible and combustion product after heating: 37.8901g
What experimental evidence would best help confirm that a new compound had been made and that a chemical change occurred?
The data indicate that the combustion product has a greater mass than the reactant Mg. The Mg must have reacted with another substance to form a compound with a greater mass.
What is represented in the X and Y-intercept of a titration curve?
X-axis: degree of titration (volume)
Y-axis: pH