Name Date

Practice Problems for the Final Exam

1. Explain which piece of lab equipment would be most useful for the following tasks:(a) Putting 5 g of powder into a test tube:

(b) Measuring exactly 43mL of water:

(c) Weighing out 120g of NaCl:

(d) Removing chemicals from its bottle:

(e) Preparing a solution:

2. Label each as a physical or chemical property:(a)Melting point

(b) Ability to rust

(c) Smell

(d) Flammability

(e) Density

(f) Color

(g) Digestibility

3. Label each as an element, compound, heterogeneous mixture, or homogeneous

mixture:(a) Salad

(b) Water

(c) Salt

(d) Alphabet soup

(e) Kool-Aid

(f) Aluminum foil

4. (a) What are the 4 indicators of a chemical change?

(b) From just seeing a chemical equation like the one below, what indicators of a chemical change could you identify?

2NaHCO3 (aq) → Na2CO3 (s) + H2O (g) + CO2 (g) ΔH = +129 kJ

5. Explain how would you separate cereal, sugar, and iron. State the physical properties and separation methods used.

6. Explain how would you separate sand, water and rubbing alcohol. State the physical properties and separation methods used.

7. If 24g of carbon react with 64g of oxygen gas to yield carbon dioxide, in the equation:C + O2 → CO2

what mass of product (carbon dioxide) is formed? (HINT: Think of the law of conservation of mass. Stoichiometry is not necessary here.)

8. Draw the general layout of an atom (p+, n, e-, nucleus)

9. Explain the difference between the atomic number and mass number:

10. Calculate the atomic mass of Ag. The isotopes are Ag-107 with a mass of 106.9 amu and an abundance of 51.86% and Ag-109 with a mass of 108.9 amu and an abundance of 48.14%.

11. Calculate the atomic mass of Si. The isotopes are Si-28 with a mass of 27.98 amu and an abundance of 92.21%, Si-29 with a mass of 28.98 amu and an abundance of 4.70% and Si-30 with a mass of 29.97 amu and an abundance of 3.09%.

12. Define the difference between an orbit and orbital:

13. (a) Fill in the following energy diagram for O. (b) Identify the element in shown below.

Energy Energy

14. Write the electron configuration – both written out and in shorthand:

Zn

S

O-2

Ba

Li+1

15. Define each term below and state its trend on the periodic table.(a) Atomic Size

(b) Electronegativity

(c) Ionization Energy

16. Fill in the missing information in the table below.

Atom Atomic Number

Mass Number

# of Protons # of Electrons # of Neutrons

Ne

18

27 13

16 16 16

Co-59

7 7 8

15

5 3

I

34

9 11

25 11

Ca+2

Si-30

O-2-17

17. For each compound listed below:- say whether it is an ionic or molecular compound- name the compound- if it is a ionic compound, write what ions it is made up of- if it is a molecular compound, draw the structural formula

Compound Ionic or Molecular?

Name Ions or Structure

KCl

N2O4

Fe2O3

CO

Cs2O

18. For each compound listed below, state the total number of valence electrons, draw the Lewis structure, draw the geometry and name the geometry of the molecule.

Compound Total Valence e-

Lewis Structure Geometric Shape (draw it) Geometric Name

CO2

SO3

CH4

NH3

H2O

19. For each substance below, add any partial positive and negative charges to the structure, say whether the molecule is polar or nonpolar, and list the types of forces involved.

Structure Polar or Nonpolar? Types of Forces Involved

20. If you wanted to make a homogeneous solution using 2 of the 3 molecules in question 19, which 2 would you chose and why?

21. For the table below, fill in the missing information. If the compound is molecular, it will not have a cation or anion. In this case, put a dash.

Cation Anion Chemical Formula Name

HCl

Manganese acetate

K+ OH-

Carbon dihydrogen dioxide

AgNO3

Fe3+ SO32-

Nitric Acid

PF5

22. Describe what is happening in the chemical equation in words.(a) 2Na (s) + 2H2O (l) 2NaOH (aq) + H2 (g)

(b) 2FeCl3 (aq) + 3Ca(OH)2 (aq) 2Fe(OH)3 (s) + 3CaCl2 (aq)

23. Write the skeletal equation:(a) Sulfur burns in oxygen to form sulfur dioxide.

(b) Lithium and sulfuric acid react, catalyzed by heat, to form hydrogen gas and lithium sulfate.

24. Balance the following equations:(a) Zn(OH)2 + H3PO4 Zn3(PO4)2 + H2O

(b) C2H6 + O2 CO2 + H2O

25. Write the general type of reaction and predict the products formed. Write the states of the products only if they are necessary to determine if the reaction will happen or not.

(a) Be + O2

(b) KOH (aq) + H3PO4 (aq)

(c) C6H6 (l) + O2 (g)

(d) Fe (s) + Pb(NO3)2 (aq)

(e) HI

(f) Ba(NO3)2 (aq) + H3PO4 (aq)

(g) Cl2 (aq) + NaI (aq)

(h) Na2S (aq) + Cd(NO3)2 (aq)

(i) MgO

(j) C7H16 (l) + O2 (g)

(k) MgSO4 (aq) + Cu (s)

(l) CaBr2 (aq) + AgNO3 (aq)

(m) C3H6 (l) + O2 (g)

(n) Al + Cl2

(o) CaI2 (aq) + Hg(NO3)2 (aq)

26. Write the complete and net ionic equations for the precipitation reaction below.3Ca(OH)2 (aq) + 2H3PO4 (aq) Ca3(PO4)2 (aq) + 6H2O (l)

27. What is the density of an irregularly shaped object that weighs 5.8g and displaces 13mL of water?

28. Write the appropriate number of significant figures for each measurement and estimate the uncertainty.

(a) (b)

29. Covert the following:

(a) 157 cs to s

(b) 42.7 L to mL

(c) 64 g of NaCl to compounds

(d) 5L of hydrogen at STP to g

30. What are the representative particles for the following things?(a) FeO2 (b) CO2

(c) Al (d) NH3

31. The compound methyl butanoate smells like apples. Its percent composition is 58.8% C, 9.8% H, and 31.4% O. Its molar mass if 102 g/mol. What is its empirical formula? What’s the molecular formula?

32. Muscle fatigue can result from the buildup of lactic acid resulting from overexercising. The percent composition of lactic acid is 40.0% C, 6.67% H and 53.3% O. What is the molecular formula of lactic acid if its molar mass is 90.0 g/mol?

33. Ammonia is produced by the reaction:3 H2(g) + N2(g) 2 NH3(g)

If 55.6 g of H2(g) reacts with excess N2(g), what is the theoretical yield of NH3(g)?What is the percent yield if the actual yield of the reaction is 295 g of NH3(g)?

34. Methyl alcohol (wood alcohol), CH3OH, is produced via the reactionCO(g) + 2 H2(g) CH3OH (l)

A mixture of 1.20 g H2(g) and 7.45g CO(g) are allowed to react. The actual yield is 7.52g of CH3OH. What is the % yield?

35. Predict the products for these neutralization reactions:

a. Be(OH)2 + HCl

b. H2SO4 + KOH

36. Calculate the pH for the following concentrations and state whether the solution is acidic or basic:

a. [H+] = 1.0 x 10-4

b. [H+] = 3.0 x 10-10

c. [H+] = 5.0 x 10-5

37. Describe how you would prepare 100 mL of a 6 M solution of KOH (starting with KOH powder). Be specific (include specific numbers and lab equipment you would use).

38. If 190.3 g of MgCl2 is dissolved in 2.0 L of water, what is the concentration of the solution?

39. How much water would need to added to dilute 500 mL of a 2.4 M KCl stock solution to make a 1.0 M solution?

40. If 25 mL of water is added to dilute 125 mL of a 0.15 M NaOH solution, what will the concentration of the resulting diluted solution be?

41. (a) (3 pts) Write the balanced neutralization reaction of sulfuric acid and sodium hydroxide.

(b) (3 pts) In a titration experiment involving the neutralization reaction from part a, the equivalence point was reached when 7 mL of 2M sodium hydroxide was titrated with 25 mL of sulfuric acid. What is the concentration of the sulfuric acid?

42. Label the following as either endo- or exothermic reactions:a. A candle burning

b. The melted candle wax solidifying

c. Two substances chemically react in a beaker; the beaker is warm to the touch

d. An instant cold-pack

e. Baking a potato

f. Burning a match

g. Evaporating alcohol

43. How much heat does 32 g of a metal absorb when it is heated from 25 oC to 80 oC? The specific heat of the metal is 0.18 J/g oC.

44. You place a piece of metal into 300 g of water at 25 oC. The water cools to 7 oC. How much heat is transferred. Is this an endothermic or exothermic change for the metal?

45. Fill in the table of hydrocarbons below with the missing in formation (shorthand structure, Lewis structure, or name.

Shorthand Structure Lewis Structure Name

----- N/A ---- methane

46. Give the general name of the compound for each below.

(a)

(b)

(c)

(d)