Final Exam (format)

Mr. Bartelt’s chemistry class Unit 7 Exam: Nuclear chemistry Name:____________________

Date:_________

Score:________

/100

This exam will cover all the major concepts that we have learned in this class. You may use the note sheet that we developed in class and the formula sheet that I have provided. You have 90 minutes to complete this test. Good luck. Short answer: Answer 15 of the 25 questions. Indicate which items you want to have graded by circling the number with a highlighter (I’ll provided it). Only the first 15 circled items will be graded and scored. This section is worth 45 points. 1) How many significant figures are in the number _____? (1 pt) Put it in scientific notation. (1pt)

2) How many significant figures are in the number ____? (1 pt) Put it in scientific notation. (1pt)

3) You find that sample of a solid substance has a volume of ____ ml. You weigh it and find that it has a mass of ____ grams. What is its density? (2pts) Would this substance float? Why? (1 pt)

4) Explain how ___________ experiment lead to the discovery of the nucleus/electrons/other atomic model. (3pts)

5) Find the mass of ________ X atoms. # of atoms moles (2pts), molesgrams (1pts)

6) Write the electron-configuration notation (1s22s22p6…) for X. (2pts) Explain how this gives rise to a certain chemical property. (1pt)

7) Correctly fill in the orbital diagram for X. (3 pts) Also show the correct configuration for carbon when it’s sp3 hybridized. 1s 2 s 2 p 2 p 2 p Ground state

1s 2 sp 2sp 2sp 2sp Hybridized

8) Identify the four blocks (s,p,d,f) on the periodic table below. (3 pts) SHAPE \* MERGEFORMAT

9) How many bonds would you expect X to from?(2pt) Why? (1pt)

10) How does atomic radius/ionization energy/electronegativity change as you move across the periodic table?(1pt) as you move down the periodic table? (1pt) Why? (1pt)

11) What is the difference between ionic and covalent bonds? (3pts)

12) Predict whether the following bonds will be ionic or covalent. (1pt each) X-Y

__________(there will be three of these)

13) Draw a Lewis structure for easy (1pt), medium (1pt), and hard (1pt).

14) a)Draw the Lewis structure for hard (1pt). b)Show the correct resonance structure. (1pt)

c)Draw the correct Lewis structure for (an anion). (1pt)

15) What geometry would you expect from the following molecules? (1 pt each) X#Y#Z# _____________ (There will be three) 16) Write: (1pt each) the compound formed by X and Y ions

________________________

_________ in its molecular formula

________________________

the name of the following compound: _____

________________________

17) What is the oxidation number of X in _____? (2pts) Y in _____? (2pts)

18) Find the mass of _____ moles of X. (3pts)

19) Balance the chemical equations below: (2pts) Name the reaction type. (1pt) Chemical reaction

________________________

20) State whether the following phase changes are endothermic or exothermic (1pt each) Phase change

____________________

21) a) If pressure/temp/volume increases/decreases at constant pressure/temp/volume, then pressure/temp/volume will ↑ or ↓ (circle one, 1pt) (there will be three) 22) A gas is collected by water displacement at ____ C under ___ torr of pressure. What would the partial pressure of the gas be under these conditions? (3 pts)

23) Balance the nuclear reaction below: (2 pts) What type of reaction is this? (1 pt) __ __

__ __ →__ __ + __ __ __

Reaction type=_______________ 24) State what conditions give rise to each of the following nuclear reactions. (1pt each) Alpha decay

____________________________________________________

Beta decay

____________________________________________________

Electron capture/positron emission

____________________________________________________

25) Surprise (5 pts)

Calculation problems: Answer 2 of the 6 questions. Indicate which items you want to have graded by circling the number with a highlighter (I’ll provided it). Only the first 2 circled items will be graded and scored. This section is worth 25 points. If you attempt two 10 point questions then you won’t be able to make up those other five points. If you attempt both 15 point problems then you may earn up to 30 points in this section. Indicate which problems you have attempted and do them on a separate sheet of paper. Only that separate sheet will be graded. 1) Quantitative analysis shows that a compound contains: ____% H, ____% C, ____% N, and ____% O Upon further investigation, it was discovered that our molecule has a molar mass of ____ g/mol. Determine the molecular formula of your molecule. (15 points) Convert % to grams (2 pts) Convert to moles (5 pts) Determine empirical formula (4 pts) Determine molecular formula (3 pts) Clear work (1 pt)

2) How many grams of water would be produced if ___ grams of ____ were reacted? (15 pts)

reactants  products a) Convert grams ____ to moles b) Correct mole ratio c) Covert moles ____ to grams d) Correct units and sig figs

(3pts) (3pts) (3pts) (1pt)

3) Translate the word equation, predict the products of the double replacement, and balance: (10 pts) Reactants (in words) 

4) What volume would you expect ____ moles of gas at ____ °C, and ____ atm of pressure to occupy? (10 pts)

5) A gas is collected in a spherical container under _____ (units) of pressure. What would the diameter of the sphere need to be if the temperature of the gas were ____ °C? (15 pts)

6) A wooly mammoth is unearthed. His skin contains ____ grams of carbon-14. Had it died yesterday it would have contained _____ grams of carbon-14. How old is the carcass? Half-life of carbon-14 is 5730 years.