Quantities Unit Flashcards
What is the number of Avogadro’s number?
6.022 x 10^23
What is Avogadro’s number (define)
the number of atoms in 12.01 grams of Carbon
What is the Equation for mols avogadro?
n = N/NA (mols = molecules / Avogadro)
What does the symbol N stand for?
molecules, atoms, particles, formula units
what are ATOMS?
Pure, monoatomic elements such as Fe or Na
what are FORMULA UNITS?
Pure ionic compounds like NaCl
A particle composed of two or more nonmetal atoms is a ______?
MOLECULE!
what is the formula for finding mols using mass?
n = m / M (mols = mass / molar mass)
Equation for %composition?
Mass/molar mass of the element youre looking for / m/M of compounds x 100
(m of element/m of cmpd x 100)
what does the empirical formula show?
Shows smallest whole number ratio of each element in a cmpd
what does the molecular formula show?
Sows the actual number of atoms of each element in a cmpd
How do you find the empirical formula?
0.5. the % total should equal 100. % # becomes g.
1. det M of each element
2. find mols of each
3. divide mols by smallest mol
4. round to nearest whole and add to cmpd accordingly
How do you find the molecular formula?
- find mols of each element
- divide mols by smallest
- add to element
- find M of this found cmpd (EF)
- experimental M (should be found in question) / empirical M (EF) = A
- multiply A to the #’s in the EF
How do you find the limiting reactant
- find mols of reactants
- divide both by the known coeff
- multiply both by a chosen unknown coeff
- whichever number is lower is your answer
what is theoretical yield
the amount of product that is predicted by stoichiometric calculations
