Review/Miscellaneous
How many Carbon atoms are in the following compound: Fe2(CO3)3
What is...
3 Carbon atoms
This represents the number 6.02 x 1023. It is also known as Avogadro's (Avocado's Number).
What is...
a mole.
For the molecule, N2O5, how many atoms of Oxygen atoms are there in 1 molecule of N2O5?
What is...
5 atoms
Convert 11.2 Liters of CO2 gas to Moles of CO2 gas.
What is...
0.5 Liters of CO2 gas
What is the empirical formula of C4H10?
What is...
C2H5
Avogadro's number is used with what units?
(moles, liters, molecules, atoms, grams)
What is...
Molecules AND atoms
The conditions meant by STP for gases (Standard Temperature and Pressure)
What is...
0o Celsius and 1 atm
For the molecule, N2O5, how many moles of Oxygen atoms are there in 1 mole of N2O5?
What is...
5 moles of Oxygen
What is the mass of 0.87 moles of NH3?
What is...
14.82 grams
***remember that when the problem is asking for "mass" you need to use the Molar Mass to convert.
What is the empirical formula of dinitrogen pentoxide?
What is...
N2O5....its the same!!
Why do we use Avogadro's number?
What is...
Because atoms are very very very very very small.
It makes the numbers easier to work with.
This refers to the lowest whole-number ratio of the atoms or moles of the element. (one of the two chemical formulas we discussed)
what is...
the empirical formula
What is the formula mass for AgNO3 (silver nitrate)?
What is...
169.88 amu (atomic mass units)
What is the percent composition of all the elements in glucose (C6H12O6)?
What is...
39.7% Carbon; 53.6% Oxygen; and 6.8% Hydrogen
The molecular formula is a simple ________ - _______ ratio of its empirical formula
whole number
How many zeroes are in Avogadro's number?
What is...
22!
6 0 2 000,000,000,000,000,000,000
This refers to the actual chemical formula for a compound
what is...
the molecular formula.
What is the Molar Mass of lead (IV) nitrate [Pb(NO3)4]?
What is...
455.24 g/mol
Convert 3.05 x 1025 atoms of Carbon to grams of Carbon.
What is...
608.5 grams
***if "moles" is not listed in the problem, it is most likely a 2-step conversion problem
What is the percent composition of KClO3? (Potassium, Chlorine, and Oxygen)
What is...
31.9% K; 28.9% Cl; and 39.2% O
How do you balance the following equation?
C3H8 + O2 ----------> CO2 + H2O
What is...
2 C3H8 + 10 O2 ----------> 6 CO2 + 8 H2O
(Don't worry...no balancing on the test!!)
This refers to the relative amounts of the elements in a compound.
What is...
the percent composition
What is the formula mass AND what is the molar mass of BrCl3?
What is...
186.25 amu AND 186.25 g/mol
Convert 3 L of H2 gas to grams of H2 gas.
What is...
0.27 grams of H2 gas
***Remember...if there "moles" is not in the problem, it is a 2-step conversion problem.
If a 13 gram sample contains magnesium and oxygen decomposes, 5 grams of oxygen is obtained. What is the percent composition of the compound?
What is...
38.5% Oxygen; 61.5% Magnesium
***fine the mass of all the elements, then find the percents (percent/whole)