Chapter 4 Flashcards
What do the coefficients in a chemical reaction specify?
The relative amounts of moles of each of the substances
How do you solve an equation that gives you a certain mass of a starting product and asks for the end result mass of another product?
Convert first product to moles, use mole ration of two compounds to find moles of the end compound, find mass of end compound using molar mass
What is the theoretical yield?
The amount of product that can be made in a chemical reaction based on the amount of the limiting reactant
What is the actual yield?
The amount of product produced after it undergoes a real experiment
What is the percent yield?
The actual yield divided by the theoretical yield multiplied by 100
It is the percentage of the theoretical yield that was actually attained
Why is an aqueous solution?
A substance in which water acts as the solvent
What is a dilute solution?
A solution that contains a small amount of solute relative to the solvent
What is a concentrated solution?
One that contains a large amount of solute relative to the solvent
What’s is molarity (M)
The way to express a solutions concentration
Amount of solute (mols) divided by volume in solution (L)
What is the solution solution equation with molarity and volume
M1V1=M2V2
Does the number of mols change when diluting a solution?
No
M1V1=M2V2
Mols1=Mols2
What are electrolytes
Substances that dissolve in water to form solutions that conduct electricity
What are strong electrolytes?
Substances that completely dissociate into ions when they dissolve
What are nonelectrolytes?
Compounds that do not dissociate into ions when dissolved in water
What are acids?
What’s a strong acid? Weak acid?
Molecular compounds that ionize when they dissolve in water
A strong acid completely ionizes in a solution
Weak acids do not completely ionize
What are the 6 general solubility rules? IN ORDER
- All Na, K, Li, and NH4 salts are soluble
- All nitrates (NO3) and acetate (C2H3O2) salts are soluble
- Ag, Pb, and Hg(I) salts are insoluble
- Chlorides, bromides, and iodides are soluble
- Carbonates, sulfides, phosphates, oxides, and hydroxides are insoluble
- Sulfates are soluble except for Ca, Sr, Ba, and Ag salts
What type of compounds form precipitates?
ONLY INSOLUBLE COMPOUNDS
If all possible products are soluble when determining a precipitate reaction, what do you write after the arrow?
No reaction
What do acids produce in a solution? What about bases?
Acids- H+ or H3O
Bases- OH-
What are some common acids and names?
HCl- hydrochloric acid HBr- hydrobromic acid HI- hydroiodic acid HNO3- nitric acid H2SO4- sulfuric acid HClO4- perchloric acid HCHO2- formic acid HC2H3O2- acetic acid HF- hydrofluoric acid
What are some common bases and names?
NaOH- sodium hydroxide LiOH- lithium hydroxide KOH- potassium hydroxide Ca(OH)2- calcium hydroxide Ba(OH)2- barium hydroxide NH3- ammonia
When a base and an acid combine what will they always produce?
H2O + compound (salt)
Acid + base -> water + salt
What are the main types of compounds that form gases in aqueous reactions?
Sulfides - H2S gas’s produced
Carbonates and bicarbonates- CO2 has produced
Sulfites and bisulfites - SO2 gas produced
Ammonium- NH3 gas produced
What is a combustion reaction?
The reaction of a substance with O2 to form one or more oxygen containing compounds
What is a gas evolution reaction?
Aqueous reactions that form gas when two solutions are mixed
Do all gas evolution reactions form gas directly?
No sometime they produce an intermediate compound that when broken up equals the gas and water (H2O)
