1. Chemistry Final Exam review

2. Convert the following:
0.5 mol of Zn to g
1.5x1023 molecules of NaCl to g
15.5L of Cl2 gas at STP to molecules
32.7g Zn
14.56 g NaCl
4.17x1023 molecules Cl2

3. A neutral atom of element number 50 with a mass number of 120 contains how many protons, neutrons, and electrons?
50 protons, 50 electrons, 70 neutrons

4. Which measurements are invalid? Why?
-Tony, Emily, Dionne
-The ruler is calibrated to the ones place so the uncertain digit is the tenths place

5. Convert 5.0 kg to cg
5.0 kg = cg

6. What are the units of molar mass?
g/mol

7. Calculate the molar mass of sodium acetate.
82.03 g/mol

8. How many significant figures?
2.60 x 1012 km
500 cm g 2 3 1 5

9. What is the most dense part of an atom that contains nearly all of its mass?
The nucleus

10. What are the 3 particles that make up an atom? What are their charges?
Proton +
Neutron 0
Electron -

11. Salt (NaCl) and Water (H2O) would both be classified as __________
Salt (NaCl) and Water (H2O) would both be classified as __________. But together, they form a solution, which would be classified as a __________.
Choose from: elements, compounds, homogeneous mixture, heterogeneous mixture
Compounds, homogenous mixture

12. A neutral atom of element number 50 with a mass number of 120 contains how many protons, neutrons, and electrons?
50 protons, 50 electrons, 70 neutrons

13. If the volume of a tire is increased, what will happen to the pressure
If the volume of a tire is increased, what will happen to the pressure? Why?
It will decrease, the particles are colliding less with the sides of the container

14. Columns on the periodic table represent ________ while rows represent _______.
Groups, periods

15. Which group of elements are essentially non-reactive? Why?
The noble gases (group 8). They have 8
Valence electrons (a full shell)

16. Which group of the following elements has the greatest electronegativity?Cl Cu Ba Zr
a. Cl

17. What is the concentration of a solution that contains 25
What is the concentration of a solution that contains 25.0g of sodium chloride in 750mL of water?
0.67 M

18. What is the intermolecular force present between hydrofluoric acid (HF) molecules? Why?
H-Bonding, it is a polar molecule with a H bound to a F, N or O

19. The amount of energy required to raise the temperature of 1g of a substance by 1oC is the substance’s ___________.
Specific Heat

20. The theoretical yield of a chemical reaction is determined by the ____________.
Limiting reagent.

21. A gas as a temperature of 14oC and volume of 4. 5 liters
A gas as a temperature of 14oC and volume of 4.5 liters. If the temperature is raised to 29oC, what is the new volume of gas?
4.74 L

22. The specific heat of gold is 0
The specific heat of gold is g/JoC while the specific heat of aluminum is g/JoC. Which one will take longer to heat up? Why?
Gold. It has a higher specific heat so it takes more energy to raise its temperature.

23. What is the definition of temperature?
Average Kinetic Energy

24. What are the 2 main types of compounds? Define them.
Ionic: metal and a non metal
Covalent: two non metals

25. Determine if the following compounds are polar or nonpolar. -HF. -N2
Determine if the following compounds are polar or nonpolar. -HF -N2 -PCl3 -CH4
-Polar
-Nonpolar

26. What is the pH and pOH of a 1.2x10-3 M HBr solution?
pH = -log(1.2x10-3) = 2.92
pOH = = 11.08

27. DO NOT ERASE YOUR ANSWER!
Lithium hydroxide combines with lithium chloride. I begin the reaction with 20g of lithium hydroxide. What is the theoretical yield of lithium chloride?
DO NOT ERASE YOUR ANSWER!
35.4g LiCl

28. From the previous problem, I actually produced 6g of LiCl
From the previous problem, I actually produced 6g of LiCl. What was my percent yield?
16.9%

29. If I have 4 moles of a gas at a pressure of 5
If I have 4 moles of a gas at a pressure of 5.6 atm and a volue of 12 L, what is the temperature?
204.6 K

30. DO NOT ERASE YOUR ANSWER!
What is the empirical formula of a molecule containing 65.5% C, 5.5% H, and 29.0% O?
C3H3O
DO NOT ERASE YOUR ANSWER!

31. If the molecular mass of the actual molecule is 110 g/mol, what is the molecular formula?
C6H6O

32. If you add 30g of KCl to 100mL of water at 80o, what type of solution is this?
Unsaturated

33. Another word for an acid base reaction?
Neutralization reaction

34. An acid and base react to form magnesium carbonate
An acid and base react to form magnesium carbonate. Write and balance the reaction.
Mg(OH)2 + H2CO3  2 H2O + MgCO3

35. Draw the orbital notation for cobalt.4s 3s 3p 2s 2p 1s

36. What is the relationship between wavelength and frequency?
Inverse. As wavelength gets longer, frequency gets lower.

37. Write the noble gas configuration for mercury
Hg: [Xe] 6s25d10

38. Who is credited with establishing the atomic theory?
Dalton

39. How many grams of carbon dioxide gas are present if it is at a pressure of 1.2 atm, a volume of 31 L and a temperature of 87oC.
n = 1.27 mol  55.88g CO2

40. How much heat is required to cool then completely freeze 300g of water at 50oC?
Q = J

41. A 230g sample of lead is heated to 58oC then placed in a calorimeter of water at 22oC. The temperature eventually reads 30oC. What mass of water was used?
24.8g of Water

42. Write the electron configuration for Iron.
1s22s22p63s23p64s23d6

43. Heat solid magnesium in the presence of oxygen gas to form magnesium oxide. You start with 32.5 g of each reactant, what is the limiting reagent?
Magnesium

44. Heat solid magnesium in the presence of oxygen gas to form magnesium oxide. You start with 32.5 g of each reactant, what is the theoretical yield of magnesium oxide?
53.9 MgO

45. Solid tin is added to aqueous sodium acetate. Will this reaction occur
Solid tin is added to aqueous sodium acetate. Will this reaction occur? Why or why not?
No, sodium is higher on the activity series.

46. Which salt has the greatest solubilty in 100mL of water at 10oC?KI

47. Describe a solution of KClO3 that contains 20g of solute in 100 g of water at 80oC.
Unsaturated

48. Draw the lewis structure of the following compounds and indicate their molecular shapes:
a. H2S
b. NCl3
Bent
Trigonal pyramidal