107 exams

 

Chemistry 107                                                        Final Exam                                                    May 2, 2016

 

1- A liquid has a density of 1.231 g/mL. What volume, in mL, contains 125.0 g of the liquid?

 

                     101.5 mL

 

 

2- A speed of 64 cm/sec is what when expressed in units of meters/minute?

 

                     38.4 m/min

 

 

3- Which one of the following is the symbol of a halogen?

 

          1) Ca            2) Cl            3) Ha            4) C

 

4- Give the name for the compound CaCl2.

 

 

    Give the formula for hexaphosphorous tetroxide.

 

 

 

5- How many moles are there in 21.0 g of Ca(OH)2?

 

                     0.284 mol

 

 

6- How many grams of H2O can be produced from 30.0 g of O2 and 25.0 g of H2 using this reaction?

2 H2 + O2 → 2 H2O   (This is a multiple choice question but show your work in case I need to give partial credit.)

1) 225 g       2) 33.75 g    3) 258.75 g  4) 15.9 g

 

                     33.75 g

 

 

 

 

 

 

 

 

7- Indicate the type of reaction that each of the following is: precipitation; acid-base; redox.

          2 H2 + O2 → 2 H2O

 

          Ba2+ + CO32- → BaCO3

 

          HF + OH¯ → H2O + F¯

 

8- What is produced when CH4 is burned in a combustion reaction?

 

    1) CO2 only                  2) CO2 and O2                  3) CO2 and H2O          4) H2O only

 

 

 

 

 

 

9- What volume of a 0.500 M HCl solution is needed to neutralize 10.0 mL of a 0.300 M Ca(OH)2 solution?        2 HCl(aq) + Ca(OH)2(aq) → 2 H2O + CaCl2(aq)

 

                     0.0120 L

 

 

 

 

 

 

 

 

 

 

 

10-     What volume will 2.00 mol of an ideal gas occupy if it is kept at a pressure of 3.20 atm and a temperature of 325 K?

 

 

                     16.7 L

 

 

 

11-     A sample of 12.0 g of a gas occupies a volume of 0.650 L at a pressure of 0.78 atm and temperature of 303.0 K. What is the molar mass of the gas?

 

 

                     589 g/mol

 

 

 

 

 

12-     Give two assumptions or statements of the kinetic molecular theory of gasses.

 

 

 

 

 

 

13-     How much heat is absorbed by 40.0 g of Fe when its temperature goes from 26.0°C to 38.5°C? The specific heat of Fe is 0.444 J/g°C.

 

                     222 J

 

 

 

 

DHf°

(kJ/mol)

CO

-110.5

CO2

-412.9

O2

0.0

14-     Use the heats of formation given to calculate the DHreaction for this reaction:

                               O2 + 2 CO → 2 CO2

     1)  604.8 kJ/mol

     2)  -1046.8 kJ/mol

     3)  -604.8 kJ/mol

     4)  -302.4 kJ/mol

 

                               -604.8 kJ/mol

 

 

15-     An electron in an s sublevel occupies a region that is:

     1) spherical

     2) circular

     3) double lobes

     4) disk shaped

 

16-     Give the number of p electrons and the number of d electrons in an atom of Sb(#51)

     1)  three p electrons, no d electrons

     2)  21 p electrons, no d electrons

     3)  21 p electrons, 20 d electrons

     4)  three p electrons, 20 d electrons

 

17-     a)       Which is larger: Na or Na+?

 

     b)  Which is larger: Br or Br¯?

 

18-     How many unshared pairs of valence electrons (Lewis dots) are there in the Lewis dot structure for a Cl2 molecule?

     1) 1         2) 4       3) 6      4) 8

 

19-     Give the Lewis dot structure for C2H2. Each C atom is attached to a C atom and a H atom.

 

 

 

 

 

 

 

20-     Give the Lewis dot structure for BF3.

 

 

 

 

 

 

 

 

21-     Draw and explain the molecular geometry of a PF5 molecule.

 

 

 

 

 

 

 

 

 

22-     Draw and explain the molecular geometry of an NH3 molecule.

 

 

 

 

 

 

 

 

 

23- What are the hybrid orbitals of the carbon atoms in this molecule: CH3CH=O?

     1)  sp3 and sp3

     2)  sp2 and sp

     3)  sp3 and sp

     4)  sp3 and sp2

 

24-     a)       How many sigma(s) bonds are there in this molecule?

     b) How many pi(p) bonds are there?       

 

                      H  H

                    H-C=C-C≡C-H

 

 

 

 

R = 0.0821 Latm/molK