Monday
February 4, 2013
(Mass to Mass
Stoichiometry)
Bell Ringer
Monday, 2-4-13
When 100.0 grams of lithium metal reacts with
oxygen gas in a synthesis reaction, how many
moles of product are produced?
4 Li +
O2 æ 2Li2O
7.19 moles of lithium oxide
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school today until 4:45.
Assignment
Currently Open
Summative
or
Formative?
Date
Issued
Date Due
Date Into
GradeSpeed
Final Day
QUIZ 16
S1
1/18
1/18
1/24
THURSDAY
WS – Mole to Mass
Stoichiometry
F11
1/30
2/1
FRIDAY
WS – Mass to Mole
Stoichiometry
F12
1/31
2/5
FRIDAY
QUIZ 17
S2
2/1
2/1
2/1
2/15
Types of Stoichiometry Problems
Mass – Mass Conversions: Given is a
mass in grams and the unknown is a
mass in grams.
When you are given the mass of one substance
and asked to calculate the mass of another
substance in the chemical reaction, the general
plan is:
Mass-Mass Calculations
The following is a solution plan for problems in which
the given quantity is expressed in grams and the
unknown quantity is also expressed in grams.
Mass-Mass Calculations
Sample Problem
Tin (II) fluoride, SnF2, is used in some
toothpastes. It is made by the reaction
of tin with hydrogen fluoride according
to the following equation:
Sn + 2HF → SnF2 + H2
How many grams of SnF2 are produced
from the reaction of 30.00 g of HF with
Sn?
Mass-Mass Calculations
Sample Problem
Tin (II) fluoride, SnF2, is used in some toothpastes. It is made by
the reaction of tin with hydrogen fluoride according to the
following equation:
Sn + 2HF → SnF2 + H2
How many grams of SnF2 are produced from the reaction of 30.00
g of HF with Sn?
Given: amt of HF = 30.00 g
Unknown: mass of SnF2 produced in grams
Mass-Mass Calculations
The conversion factors needed are the molar
masses of HF and SnF2 and the mole ratio of
SnF2 to HF.
Mass-Mass Calculations
Use the periodic table to compute the molar
mass of HF and SnF2.
Mass – Mass Conversions
Sample Problem
In the following reaction, how many grams of SnF2 are
produced from 30.00 grams of HF?
Sn + 2HF → SnF2 + H2
30.00g HF / 20 g/mol HF = 1.50 mol HF
Mole ratio of SnF2 to HF = 1:2
Molar mass of SnF2 = 156.71 g/mol
1.50 mol HF x ½ x 156.71 g SnF2 =
117.56g SnF2
Worksheet
Mass to Mass Stoichiometry