ch. 4 learnsmart part 1
What information can be gained from a balanced chemical equation?
* The relative quantities (moles) of substances involved * The identities of substances involved * The physical states of reactants and products, often, but not always included.
to present a chemical change quantitatively, an equation must be balanced meaning....
...meaning the same number of each type of atom must appear on both sides.
in a balanced equation, the amounts (mol) of substances are stoichiometrically equivalent to each other which means...
...which means that a specific amount of one substance is formed from, produces, or reacts with a specific amount of the other.
3 step process to find the overall percent yield
1. express the yield of each step as a decimal 2. multiply all the decimal amounts together 3. convert back to a percentage OR!! simply multiply the individual % yields by each other.
What, in order, are the steps necessary to solve for the mass of a product, or second reactant required, given the mass of one of the reactants in a chemical equation?
1. write a balanced equation for the reaction 2. convert the given mass into moles using molar mass. convert moles of A to moles of B using a conversion factor derived from the balanced equation. 3. convert the moles of the second substance to mass using its molar mass.
Chemical equation
a statement that uses formulas to express the identities and quantities of substances involved in a chemical or physical change.
Isomers
compounds with the same molecular formula, and thus molar mass, but different properties.
the compounds depicted are ________ isomers because they have the same _______ formula but have different _________ formulas.
constitutional, molecular, structural
percent yield
is the actual yield expressed as a percentage of the theoretical yield
which of the following actions are permitted in balancing a chemical equation?
multiplying al coefficients by a common factor & inserting coefficients in front of formulas of reactants and products.
A chemical equation must be balanced. This means that the same _____ and ________ of atoms must appear on both sides of the equation.
number; type
True or false: the percent yield (% yield) is ALWAYS less than 100%.
true
How do constitutional or structural isomers occur?
when the atoms link together in different arrangements.