Chemistry Chapter 10
What is is the volume of 1 mole at STP?
1 mole = 22.4 L
The sum of the percentage in the percent compositions of a substance equals?
100
Calculate the volume of 76.1 g SO2 at STP?
26.6 L SO2
What is the empirical formula of a compound whose molecular formula is C2Cl6?
CCl3
What is molecular formula?
the actual ratio the elements can be found in a compound
What's in a mole of formula units?
the label of formula units is used with ionically bonded atoms
What's in a mole of atoms?
this label is used when dealing with elements by themselves
Just like solids have a molar mass, gases have what two things?
a molar volume and STP
What is the mole?
a way to count particles
How do you find out the number of atoms? For example, how many atoms are in 1 mole of H20?
add together the subscripts, there are 3 moles of atoms in H2O
What is the mole central to?
all of our calculation, so we can covert everything to the mole
What is the label/units for formula mass?
amu, atomic mass units
What does amu stand for?
atomic mass units
How is molar mass calculated?
calculated the same way as formula mass, just different units (g/mol) (1 mol= __________g)
What is formula mass?
defined as teh sum of the atomic masses of all the atoms in a compound
Why was atomic mass units developed?
developed because the actual mass of an atom was so small
The _____ is the simplest whole-number ratio of atoms in a compound?
empirical formula
What are the three steps to find percent composition?
find the molar mass of the compound mass of the element divided by the molar mass multiply by 100% get percentages
The sum of the atomic masses of all the atoms in a compound is called the?
formula mass
What kind of particle is represented by a formula unit ?
ionic
The molar mass of a compound depends upon the ?
mass of each element in the compound
The molecular formula of a compound can be determined by comparing the empirical formula mass with the?
molar mass of the compound
The actual number of atoms of each element in a molecular compound is given by the ___?
molecular formula
A mole of carbon dioxide contains 6.02 x 10^23 _____?
molecules because it is covalently bonded
What are the three way to describe the makeup of chemicals?
percent composition, empirical formula, and molecular formula
What does STP stand for?
standard temperature and pressure
What is percent composition?
tells what percent the elements are in a compound
What is molar volume?
the amount of gas one mole occupies at STP
What's in a mole of molecules?
the label of molecule is used with covalently bonded atoms
What is atomic mass?
the mass of each atom in amu
What is molar mass?
the mass of one mole of a substance
What is empirical formula?
the smallest ratio the elements can be found in (reduced down)
Can empirical formulas be hte same as molecular formulas?
they can be the same, but this isn't always true
How many formula units are in 3.51 grams of Silver Nitrate?
1.24 x 10^22 formula units AgNO3
How many moles of Chlorine ions are in 1 mole of CaCl2?
2 moles of Cl- ions
The molar volume of a gas at STP is?
22.4 L/mol
A sample of ammonia contains 7.22 moles of ammonia. How many molecules of ammonia are in the sample?
4.35 x 10^24 molecules NH4
What does 1 mole of an elements equal?
6.02 x 10^23 atoms
What is 1 mole of ionic substance equal to?
6.02 x 10^23 formula units
What does 1 mole of a molecule equal?
6.02 x 10^23 molecules
Besides being 1 mole, what is 6.02 x 10^23 called?
Avogadro's number
Which is a possible molecular formula of a compound whose empirical formula is CH?
C2H2
What are the 3 basic steps to finding the Empirical Formula of a compound?
Convert % of each element to grams Convert grams to moles of each element Divide by the smallest number of moles If the number is a whole number, use it as the subscript for that element If the number isn't a whole number, multiply it to get a whole number (you have to multiply all number by the same number)- then use it as a subscript
What are the 4 basic steps to find molecular formula from the empirical formula?
Find the Empirical Formula Calculate the Empirical Formula mass (add it up and find the molar mass) Divide the molar mass (that was given to you) by the empirical formula mass This should give you a whole number, so use this number to multiply the subscripts of the empirical formula
What is standard temperature and pressure (STP)?
0 degrees Celsuis 1 atmosphere (1 atm)
Standard pressure is _____?
1 atm
