Chapter 3 Flashcards
What is a combination reaction?
two or more substances react to form one product
What is a combination reaction between?
a metal and a nonmetal
What is a decomposition reaction?
one substance undergoes a reaction to produce two or more other substances
What is a combustion reaction?
proceeds with evolution of heat usually alos a flame reaction with oxygen in the burning of a match
What are the products of a combustion reaction?
CO2, H2O
What is the formula weight?(FW)
the sum of atomic weights of the atoms in the chemical formula of the substance
What is the atomic weights? (AW)
atomic weights are on the period table
What is percentage composition?
the percentage by mass contributed by each element in the substance
How to find %mass composition of element?
(number of atoms of element)(atomic weight of element)/Formula weight of substance x 100
What is avogadro’s number?
6.022 x 10^23
how to find number of atom from g?
take the g and convert it to moles then multiply by 6.022 x 10^23
What is molar mass?
Molar mass is the same as the atomic weight but in g
What is the units of molar mass?
g/mol
How to find mol of a element in a compound when given the percent of the element by mass in the compound.
change percent to g by removing the % if it is in a 100g sample then times it by the molar mass
How to find mole ratio?
divide the larger number of moles by the smaller number to obtain the ratio
After obtaining the mole ratio how do you find the emphirical formula?
find the closest number to the ratio whole number and then that equals number of each element in the compound
How do you find the whole number multiple?
molecular weight/empirical formula weight
How to find the mass of an element in the original sample when given the mass of the product?
Mass of produced x molar mass x moles produced x number of elements in molecule x moles of element in original sample x molar mass of element
How to find reactans consumed or products formed in a reaction?
g of substance A x molar mass of A x moles of A x coeffecitans from equation x moles of B x molar mass of B = g of B
What is a limiting reactant?
the reactant that is completely consumed in a reaction
What are excess reactants?
any other reactants have leftover
How to find limiting and excess reactants?
USE a BCA table
How to make a BCA table?
Before reaction: (products will =0)
Change(eaction
After reaction:(limiting will = 00
what is theoretical yield?
The quantity of product calculated to form when the limiting reactant is fully consumed
what is the actual yield?
the amount of product actaully obtained
How to find percent yield?
actual yield/ theoretical yield x 100
