Stoichiometry Flashcards
Stoichiometry is…
The relationship between the macroscopic and molecular level.
Stoichiometry allows us to… #1
Calculate how much “stuff” can be produced in a reaction…
Stoichiometry allows us to… #2
Calculate the relationship between any two components in a reaction.
We use ________ to allow us to connect from the molecular level to the observable macroscopic level.
Moles
Mole is just a number, that number is…
6.022 × 10^23
6.022 × 10^23 is also known as…
Avogadro’s Number
Balance the equation:
__N2+__O2🡪__N2O
2 N2+O2——->2 N2O
Balance the equation:
__C6H14 + __O2 🡪 __CO2 + __H2O
2 C6H14 + 38 O2 🡪 12 CO2 + 14 H2O
Balance the equation:
__FeCl3 + __NaOH 🡪 __Fe(OH)3 + __NaCl
FeCl3 + 3 NaOH 🡪 Fe(OH)3 + 3 NaCl
How many moles of calcium nitrate are in 325g? Calcium nitrate = Ca(NO3)2
Molar mass of Ca(NO3)2 = 164.09 g/mol
1 mole Ca(NO3)2 325g Ca(NO3)2 x --------------------- = 1.98 mole Ca(NO3)2
164.09 g/mol
How many moles of O atoms are in 2 mol Ca(NO3)2?
12 mol O atoms
How many atoms are 12 mole O atoms?
7.2264 x 10^24
Which of the following contains the largest number of molecules?
A. 1 mol CH4
B. 1 mol C2H6
C. 1 mol SO2
D. 1 mol CCl4
E. They all have the same number
E. They all have the same number
Which of the following contains the largest number of molecules?
A. 10.0 g CH4
B. 10.0 g C2H6
C. 10.0 g SO2
D. 10.0 g CCl4
E. They all have the same number
A. 10.0 g CH4
Study Stoichiometry Chart!
SLIDE 24-25
How many moles of NH3 would be produced if 6 moles of H2 reacted with excess N2?
Write a balanced equation for this reaction.
A. NH3 🡪 N2 + H2
B. 2 NH3 🡪 N2 + 3 H2
C. N2 + H2 🡪 NH3
D. N2 + 3 H2 🡪 2 NH3
D
How many grams of N2 are needed to react with H2 to produce 2.75 moles of NH3?
2.75 mol NH3 x ((1 mol N2)/(2 mol NH3)) x ((28g N2)/(1 mol N2))=
38.5g N2
How many moles of NH3 would be produced if 6 moles of H2 reacted with 3 moles of N2?
6 mol H2 x ((2 mol NH3)/(3 mol H2)) = 4 mol NH3
+
3 mol N2 x ((2 mol NH3)/(1 mol N2) = 6 mol NH3
___________________________________________
10 mol
When 6 mol H2 reacts with 3 mol N2,
4 mol NH3 is produced.
ALL of the limiting reactant (H2) is used up. How many moles of N2 remain at the end?
1 mol N2 = 3 mol N2 – 2 mol N2
4 mol NH3 × 1 mol N2 /2 mol NH3 = 2 mol N2
The equation for a reaction is 2 S + 3 O2 🡪 2 SO3. Which is the limiting reactant?
A. S
B. O2
C. SO3
D. There is no limiting reactant
B.
How many grams of carbon dioxide would be produced if 10 grams of methane are combusted in excess oxygen?
27.5 g
What do we use to convert from grams of methane to moles of methane?
A. Stoichiometric ratio
B. Molar mass
B.
What do we use to convert from moles of methane to moles of carbon dioxide?
A. Stoichiometric ratio
B. Molar mass
A.
How many grams carbon dioxide would be produced if an excess of methane is combusted in 10 g oxygen?
10 g O2 × 1 mole O2 / 32 g O2 ×
1 mole CO2 / 2 mole O2 × 44 g CO2 / 1 mole CO2 = 6.9 g CO2
