Matter and Measurement - PowerPoint PPT Presentation

About This Presentation
Title:

Matter and Measurement

Description:

complete all assigned homework problems. from the chapter - submit on Monday, Feb 12 ... permanganate reacts with oxalic acid in aqueous sulfuric acid according to the ... – PowerPoint PPT presentation

Number of Views:80
Avg rating:3.0/5.0
Slides: 21
Provided by: vanessa78
Learn more at: http://bohr.winthrop.edu
Category:

less

Transcript and Presenter's Notes

Title: Matter and Measurement


1
CHAPTER 4 Chemical Equations and Stoichiometry
Chapter 4 Quiz points - complete all assigned
homework problems from the chapter - submit on
Monday, Feb 12 - problems selected randomly for
grading
2
Road Map
  • Where we were
  • Balanced equations from neutral formulas,
    containing ionic equations, and one with
    polyatomic ions (Table 3.1 available on test)
  • Relationships when comparing different
    compounds, must always go through a MOLE
    comparison
  • Limiting reactant (reagent)
  • Where we are going
  • Percent yield
  • Chemical equations and chemical analysis

3
Practice Problem 4-1
  • When aqueous silver nitrate and sodium chromate
    solutions are mixed, a reaction occurs that forms
    solid silver chromate and a solution of sodium
    nitrate. If 257.8 mL of a 0.0468 M solution of
    silver nitrate is added to 156.00 ml of a 0.095 M
    solution of sodium chromate, what mass of solid
    silver chromate (M 331.8 g/mol) will be formed?
  • 2 AgNO3(aq) Na2CrO4(aq) ? Ag2CrO4(s) 2
    NaNO3(aq)

4
Practice Problem 4-1 Answer
  • 2.00 g Ag2CrO4

5
Practice Problem 4-2
  • A) If 257.8 mL of a 0.0468 M solution of lead(II)
    nitrate is added to 156.00 mL of a 0.095 M
    solution of sodium sulfide, what mass of solid
    lead(II) sulfide will be formed?
  • Pb(NO3)2(aq) Na2S(aq) ?
  • PbS(s) 2 NaNO3(aq)

6
Practice Problem 4-2 Answer
  • A) 2.89 g PbS
  • (theoretical)
  • B) Actually make 2.64g (actual)
  • What is your percent yield?

7
Practice Problem 4-2B Answer
  • B) Actually make 2.64g
  • What is your percent yield?
  • yield 100
  • yield 100
  • .9135 x 100 91.349

8
Practice Problem 4-3
  • Potassium permanganate reacts with oxalic acid in
    aqueous sulfuric acid according to the following
    equation
  • 2 KMnO4 5 H2C2O4 3 H2SO4 ?
  • 2 MnSO4 10 CO2 8 H2O K2SO4
  • If you start with 3.225 g of H2C2O4 and 75.0 mL
    of 0.250 M of KMnO4 and the percent yield is 85.3
    , what is the actual yield of CO2?

9
Practice Problem 4-3 Answers
  • 2.69 g CO2

10
Practice Problem 4-4
  • Given the chemical reaction between iron and
    water to form the iron oxide, Fe3O4 and hydrogen
    gas given below. If 4.55 g of iron is reacted
    with sufficient water to react all of the iron to
    form rust, what is the percent yield if only 6.02
    g of the oxide are formed?
  • 3 Fe(s) 4 H2O(l) ? Fe3O4(s) 4 H2(g)

11
Practice Problem 4-4 Answer
  • 95.6

12
Practice Problem 4-5
  • Ammonia is produced by the Haber process using
    nitrogen and hydrogen gas. If 85.90 g of
    nitrogen are reacted with 21.66 g hydrogen and
    the reaction yielded 98.67 g of ammonia. What
    was the percent yield of the reaction?
  • N2(g) 3 H2(g) ? 2 NH3(g)

13
Practice Problem 4-5 Answer
  • 94.49

14
Chemical Analysis
  • 72. What mass of lime, CaO, can be obtained by
    heating 125 kg of limestone that is 95 by mass
    CaCO3?
  • CaCO3 (s) ? CaO (s) CO2 (g)
  • 6.65 X 104 g CaO

15
Chemical Equation
  • A dry-cleaning solvent (M 146.99 g/mol) that
    contains C, H, and Cl is suspected to be a
    cancer-causing agent. When a 0.250 g sample was
    studied by combustion analysis, 0.451 g of CO2
    and 0.0617 g of H2O formed. Calculate the
    molecular formula.
  • Empirical C3H2Cl
  • Molecular C6H4Cl2

16
Are you up to the challenge?
  • Iodine is made by the reaction
  • 2 NaIO3 (aq) 5 NaHSO3 (aq) ?
  • 3 NaHSO4 (aq) 2 Na2SO4 (aq) H2O (l) I2
  • Name the two reactants
  • If you wish to prepare 1.00 kg of I2, what mass
    of NaIO3 is required?
  • What mass of NaHSO3?

17
p.162b
18
Next Lesson
  • Chapter 5
  • Homework due

19
Balancing Equations
  • ____C3H8(g) _____ O2(g)
    ----gt _____CO2(g) _____ H2O(g)

____B4H10(g) _____ O2(g)
----gt ___ B2O3(g) _____ H2O(g)
20
(No Transcript)
Write a Comment
User Comments (0)
About PowerShow.com