Question of the Day
A solution containing 3.50 g sodium phosphate is mixed
with a solution containing 6.40 g barium nitrate. After
the reaction is complete, 4.85 g barium phosphate are
collected.
1. What is the limiting reagent?
2. What is the theoretical yield of barium phosphate?
3. What is the percent yield of barium phosphate?
2Na3PO4(aq) + 3Ba(NO3)2(aq)  6NaNO3(aq) + Ba3(PO4)2(s)
molar masses:
Na3PO4 = 163.9
Ba(NO3)2 = 261.3
Ba3(PO4)2 = 601.9
1
Day 3 11-11
Example # 2:
What is the percent yield if 4.65 grams of copper is
produced when 1.87 grams of aluminum reacts with
an excess of cupric chloride?
Notes
page 4
ANSWER = 70.5%
Reactions that release heat are
called… Exothermic and feel hot
Reactions that absorb heat are
called…Endothermic and feel cold
Heat is a form of energy and therefore
measured in Joules (J) or
kilojoules (kJ)
Reactions that release heat are
called… Exothermic and feel hot
C3H8 + 5O2  3CO2 + 4H2O + 2043 kJ
Reactions that absorb heat are
called…Endothermic and feel cold
C + H2O + 113 kJ  CO + H2
Enthalpy – a way to measure the heat
absorbed or released in a reaction
- takes into account pressure and
volume
Kinetic Theory – Heat results from the
motion and vibration of particles of
matter
Heat = the transfer of kinetic
energy from a hotter object to a
colder object
particle collisions are the key
leads to properties of gases
Avogadro’s #
Mole ratio
Stoichiometry
6.022e23
Molar mass
Isotope
Ion
Balanced
22.4 liters
Avogadro’s law
Assignment
Review sections 12.1 and 12.2 and
complete #s 5, 6, 9, and 10 on page 389,
# 12 on page 391, and # 14 on page 393
Complete #s 21-25 on page 398
ALL due Friday 11-13
At STP 44.8 liters of water vapor
were produced via a composition
(synthesis) reaction. How many
moles of O2 were used?
Day 1 10-27 period 3
At STP 44.8 liters of water vapor were
produced via a composition (synthesis)
reaction. How many grams of H2 were
used?
Day 2 10-28
1. Is the reaction below exothermic
or endothermic? How do you
know?
2. If we wanted 2 moles of C to react
how much heat energy would need
to be added?
C + H2O + 113 kJ  CO + H2
Day 3 10-29
Go to
http://wps.prenhall.com/esm_brown_chemistry_9
/2/660/169060.cw/index.html
Choose chapter 3, click problem solving center
on the left, click and complete homework 4, click
submit answers for grading, complete homework
4 as many times as you want to until you score a
100%. When you score a 100% raise your hand
and show me your summary screen.
Assignment
Page 411 #s 41, 44, 46 (part
a only), 49, 53, 58, 60
18
Question of the Day
A solution containing 3.50 g sodium phosphate is mixed
with a solution containing 6.40 g barium nitrate. After
the reaction is complete, 4.85 g barium phosphate are
collected.
1. What is the limiting reagent?
2. What is the theoretical yield of barium phosphate?
3. What is the percent yield of barium phosphate?
19
Day 3 11-11
Question of the Day
A solution containing 3.50 g sodium phosphate is mixed
with a solution containing 6.40 g barium nitrate. After
the reaction is complete, 4.85 g barium phosphate are
collected.
1. What is the limiting reagent?
2. What is the theoretical yield of barium phosphate?
3. What is the percent yield of barium phosphate?
20
Day 3 11-11