The approximate speed of light in air is

EXAM PROBLEM #7 Instructions: Consider the molecule shown below. Answer each question by selecting the best choice from the dropdown box. There is no need to show any work on your “work” page. Note: I am unable to do any superscript formatting or insert a degree sign in the dropdowns. Molecule: Questions: A.   How many sigma bonds does the C atom have in this molecule?  [sigmaC] B.   How many pi bonds does the C atom have in this molecule?  [piC] C.   What type of orbital is the C atom using for its sigma bond(s)?  [sigmaorbitalC] D.   What type of orbital is the C atom using for its pi bond(s)?  [piorbitalC] E.   What is the bond angle for the C atom in this molecule?  [angleC] F.   What is the molecular geometry name for the C atom in this molecule?  [geomnameC] G.   What type of orbital is each Cl atom using for its nonbonding electrons?  [orbitalCl] H.   What is the angle between the electron domains that surround each Cl atom in this molecule?  [angleCl]    

EXAM PROBLEM #2 Instructions: Type your answers to the questions in the textbox below. Label your answers A and B. Show all work on your “work” page.  Label which problem it is (#2). Reaction:     4 NH3 (g)  +  5 O2 (g) –>  4 NO (g)  +  6 H2O (g)              ΔH = -906.0 kJ Questions: A.   Is heat released or absorbed by the system in this reaction? Briefly explain how you know. B.   How many grams of ammonia, NH3 must react in order for 32.41 kcal to be released or absorbed in this reaction?    

EXAM PROBLEM #3 Instructions: (1)  Type your answer to the question in the textbox below. (2)  Show all work on your “work” page.  Label which problem it is (#3). (3)  Type a degree sign by using the superscript tool with a lowercase “o”. Question: At what temperature ( in oC) will nitrogen gas have a density of 1.218 g/L if the pressure is 187.6 kPa?

EXAM PROBLEM #5 This question is one of the seven questions for which the lowest score will be dropped. Instructions: Type your answer to the question in the textbox below. Show all work on your “work” page.   Label which problem it is (#5) Situation: A large bottle contains some boric acid solution with an unknown concentration.  A 25.00 mL sample of this acid solution is titrated with a 1.438 M NaOH solution.  It takes 18.31 mL of the NaOH solution to reach the endpoint of the titration. Reaction:  H3BO3 (aq)  +  3 NaOH (aq)   –>   3 H2O (l)  +  Na3BO3 (aq) Question: What is the molarity of the unknown boric acid solution?  

EXAM PROBLEM #10 Instructions: This is a series of separate questions. Select your answers from the dropdown boxes. There is no need to write anything on your “work” page. Question 10A: Classify each of the following as an element, compound, homogeneous mixture or heterogeneous mixture. (1)   3 M HCl  [HCl] (2)   an apple  [apple] (3)  ozone, O3  [ozone] Question 10B: There are three identical containers described here: Container P has 100 moles of oxygen gas, O2. Container Q has 100 moles of hydrogen gas, H2. Container R has 100 moles of copper, Cu. (1)   Comparing the number of molecules in containers P and Q, which statement is true?  [molecules] (2)   Comparing the masses in all three containers, which statement is true?  [masses]   Question 10C: Which one of these statements best describes what happens when a teaspoon of table salt, NaCl, is dissolved in a cup of warm water?  [NaCl]

EXAM PROBLEM #6 Instructions: Write balanced chemical equations for the following reactions on your “work” page. Include reactants and products for all reactions. Include all physical states. Label which problem it is (#6) and label the answer parts A, B, C, D, E. There is no need to show any additional work on your “work” page, just the final answers. When finished, type an “X” into the textbox below so Canvas knows you have answered the question. Reactions: A.   Pb(NO3)2 (aq) +  Na2SO4 (aq) –> B.   HC2H3O2 (aq) +  Ca(OH)2 (aq) –> C.   Zn(s) +  Au(NO3)3 (aq) –> D.   Write the total ionic equation for reaction A. E.   Write the net ionic equation for reaction A.

EXAM PROBLEM #3 Instructions: (1)  Type your answer to the question in the textbox below. (2)  Show all work on your “work” page.  Label which problem it is (#3). Question: At what pressure (in psi) will fluorine gas have a density of 0.951 g/L if the temperature is 63.2 oC?  

EXAM PROBLEM #9 This question is one of the seven questions for which the lowest score will be dropped. Instructions: Type your answers to both questions in the textbox below. Label your answers A and B. Show all work on your “work” pages.  Label which problem it is (#9). Questions: The density of liquid CCl4 is 1.58 g/mL.  A sample of this liquid is 834 kg. A.   How many cubic meters is the sample? B.   How many chlorine atoms are in the sample?

EXAM PROBLEM #4 Instructions: Type your answers to the questions in the textbox below. Label your answers A, B, C, D, E, F. Show all work on your “work” page.  Label which problem it is (#4). Situation: Suppose 125 grams of O2 and 185 grams of ClO2 are combined in a closed rigid container and the following reaction occurs: 3 O2 (g)  +  4 ClO2 (g) –>  2 Cl2O7 (g) Molar masses: O2 = 32.00 g/mol  |  ClO2 = 67.45 g/mol  |  Cl2O7 = 182.90 g/mol Questions: A.   How many moles of O2 are present initially? B.   How many moles of ClO2 are present initially? C.   How many moles of O2 are present at the end? D.   How many moles of ClO2 are present at the end? E.   How many moles of Cl2O7 are present at the end? F.   What is the total pressure at the end if the container has a volume of 74.0 L and the temperature is 444 K?