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1. Calculate the volume of hydrochloric acid (HCl) 0.3 M that will neutralize 25 mL of a solution 0.1 M of Potassium hydroxide (KOH) Hint: stoichiometry with solutions or look at the calculations in titrations. 

2. Calculate the value of X for the following compounds: Hint: formula of a hydrate lab.

    1. MgSO4•XH2O, knowing that when heating 7.38 g of the compound, 3.78 g of water were collected.
    2. By Heating up 1.90 g of CaSO4 •X H2O, 1.36 g of the anhydrous compound was obtained.

3. The graph below represents a sample of a pure substance starting as a solid with uniform heating. Hint: Matter and states of the matter

    1. First, copy the diagram in a bigger size on your paper. Using a red marker/pen, represent the cooling curve of the same substance starting as a gas.
    2. Name the states of the matter present in each section of the curves (some of them has two)
    3. Mark very clear on the graph the melting point, the boiling point, the freezing point and the condensing point.

4. List the states of the matter in the graph above in DECREASING order of kinetic energy

5. If you add a crystal of solute to a solution and crystallization occurs, what kind of solution was the solution you had before?

6. Balance the following equation

         ____ NaNO3   +   ___ Ga2(SO4)3      →    ___ Na2SO4    +   ____ Ga(NO3)3

7. Resolve the following exercises:

    1. What is the total number of atoms contained in 1.50 moles of Iron?
    2. How many grams has only 1 atom of sodium? (it is NOT 23!!!)
    3. Which is the mass of 3 moles of Copper sulfate pentahydrated? (CuSO4*5H2O?
    4. How many moles of sodium chloride are there in 585 g of the compound?
    5. Which is the molar mass of a substance, if 3.00 moles of it have a mass of 540g?
    6. How many molecules of water are present in 180 g of pure water?
    7. How many atoms of He are there in 160 g of the gas?
    8. How many molecules of nitrogen gas are present in 56g of the compound?
    9. Which is the Avogadro's number? 
    10. What does it represent?
    11. How much volume occupies 3 moles of any gas at room temperature?

8. What type of bonding is present in the following compounds?

                CO2                H                  NaOH                C6H15N             CsSO4

9. All containers have the same gas X2 at different temperatures. If the pressure is the same in all of them, organize the containers in INCREASING ORDER of KINETIC ENERGY

 10. Where are the particles moving faster?

a. Ice at -2.00ºC or ice at -20.00ºC
b. Liquid water at 2.00ºC or Liquid water at 20.00ºC
c. Water vapor at 120.00ºC or water vapor at at 210.00ºC
d. Based on the answers in 9 and 10, how can you relate the temperature of a substance to the kinetic energy of the particles?

11. A group of students uses clay to make boats of different shapes. All the boats they make have the same weight.


The students add four tablespoons of salt in the water in a tank and mix the water. They place the boats in the tank and see if the boats float or sink. What can the students find out from doing just this experiment? Hint: which is the purpose of the experiment?

12. A swimming team wants to select one of three fabrics for their new swimsuits. Each   fabric is made of a different material. The team decides to do the following experiment: They cut the same size pieces from each fabric and wet each piece with the same amount of water. They hang the pieces in the sunlight and they check every two minutes to see if any of the pieces are dry.

What can the team find out about the different fabrics from doing just this experiment.

13. After some time of leaving a glass with water and ice outside in a summer day, you observe that the ice disappeared. What is the best explanation for this?

14. Write the definition and an example for the following solutions.

        1. Non saturated solution
        2. Saturated solution
        3. Super saturated solution
        4. Homogeneous mixture
        5. Heterogeneous mixture
        6. Pure substance
        7. Impurity

15. Gallium reacts with oxygen gas to form Gallium oxide, as shown in the reaction below

                                 4Ga(s) + 3O2(g)      à     2Ga2O3(s)

How many grams of gallium are needed to completely react with 384 g of oxygen?

16. Naturally occurring magnesium consists of three stable isotopes: isotope AMU abundance

      • Mg-24 =78.99%
      • Mg-25 = 10.00%
      • Mg-26 = 11.01%

What is the atomic mass of magnesium?

17. Naturally occurring lead exists as four stable isotopes: isotope amu abundance

      • Pb-204 = 1.480%
      • Pb-206 = 23.60%
      • Pb-207 = 22.60%
      • Pb-208 = 52.30%

What is the atomic weight of lead?

18. Which are metals? Circle your answers: C, Na, F, Cs, Ba, Ni

19. Which metal in the list above has the most metallic character? Explain.

20. Write the charge that each of the following atoms will have when it has a complete set of valence electrons forming an ion.             O        Na          F       N          Ca         Ar

21. What is the most common oxidation number for calcium? Explain.

22. Name two more elements with that oxidation number and explain your choice.

23. What element in period 3 is a metalloid?

24. When element with atomic number 118 is discovered, what family will it be in?

25. Make an argument for placing hydrogen in the halogen family rather than the alkali metals. Alkali metals Alkaline earth metals Transition metals Halogens Noble gases

26. Determine how many electrons were transferred to make the following ionic compounds:

NaBr ____              CaCl2 ____     Al2O3 ____     MgO ____     

27. How many electrons are lost by group IIA elements (alkaline earths) during ionic bonding?

28. How many electrons are gained by group VIIA (halogens) elements during ionic bonding?

29. A covalent bond is formed when two nonmetals _____________ valence electrons.

30. A single covalent bond has how many electrons? _____ A double covalent bond has how many electrons? _____ A triple covalent bond has how many electrons? _____

31. Calculate the percent composition of each of the elements present in the following compounds:

      1. C2H6
      2. NaHSO4
      3. Ca(C2H3O2)2
      4. HCN
      5. H2O

32. A compound of carbon and hydrogen has the composition of 9.225 g carbon and  0.768 g hydrogen.

    1. What is the empirical formula of this compound?
    2. If the compound has a mass of 52 g/mol, what is the molecular formula of the compound?

33. The compound meythl butanoate smells like apples. Its percent composition is 58.8% C, 9.8% H, and 31.4% O. If its gram molecular mass is 102 g/mol.

      1. What is its empirical formula?
      2. Which is its molecular formula?

34. Name the following compounds:

      1. Fe3(PO4)2
      2. HF
      3. CaCO3
      4. HNO3
      5. H2SO4
      6. (NH4)2S

35. Write the formulas for the following compounds:

      1. potassium chlorate
      2. Potassium Cyanide
      3. Aluminum Nitrate
      4. Carbon Tetrachloride
      5. Copper sulfate penta hydrate

36. Which are the properties of ionic compounds?

37. Which are the properties of single covalent compounds?

38. Classify the following chemical reactions: 

      1. H2 + Cl2--->  HCl(g)
      2. CH4(g) + 2O2(g) ® CO2(g) + 2H2O(g)
      3. H2O2 (l) ®  H2(g) + O2(g)
      4. Cu(s) + 2AgNO3(aq) ® Cu(NO3)2(aq) + 2Ag(s)
      5. Pb(NO3)2(aq) + K2CrO4(aq) ® PbCrO4(s) + 2KNO3(aq)
      6. Al(OH)3 + H3PO4 ® 3 AlPO4 + 3H2O


© Analia Sanchez