Chemistry Study Guide_s1_2017- (1).docx

Chemistry Study Guide – Semester 1 1. What is Chemistry about?

2. How many types of variables are there in an experiment? Define each of them with examples.

3. Convert the following standard numbers into scientific notation. a) 5300 L

b) 69 845 896 mg

d) 0.000 000 62425 kg

e) 678.3 m

c) 0.78500 dm

4. Convert each number from Scientific Notation into Standard Notation a) 1.4 mm x 10- 1 kg

b) 8.134 cm x 100 cm

c) 8.568 dg x 10-6

d) 1.2906 m x 105 s

5. Perform the following metric conversions (in scientific notation) 1 mL = ----------- L 1 L = ------------- dL 5 ng = ----------- g

15 m = ------------ mm 1μs = ------------ s 1pm = ------------ m

6. Identify the number of significant figures from the followings: a) 0.57010 g

b) 0.0026701 m

c) 19.0550 kg

d)3500 V

e)1,809,000 L

f) 9.00 x 10-3

g) 750.

7. Compare and contrast physical and chemical process with examples.

8. Compare and contrast elements and compounds.

9. Identify three characteristics for solid, liquid and gas.

10. Compare and contrast between physical and chemical properties elements and compounds. Give three examples each.

1

11. Compare and contrast between extensive and intensive properties. Give three examples each.

12. Define reversible and irreversible change with examples.

13. What is the difference between homogeneous mixtures and heterogeneous mixtures? Give three examples each.

14. What are the four indications to recognize the chemical reaction?

15. According to the conservation of mass in any chemical reaction, the mass of the products is always equal to the mass of the reactants. Hydrogen and oxygen react chemically to form water. How much water would form if 4.8 grams of hydrogen reacted with 38.4 grams of oxygen?

16. What is the formula to calculate density? What quantities do you need to measure in order to calculate the density of an object?

17. A 10.0 cm3 piece of lead has a mass of 114 g. What is the density of the lead?

18. What is the volume of a pure silver coin that has a mass of 14 g? The density of Ag is 10.5 g/ cm3

19. What is the mass, in kilograms, of 14.0 L of gasoline? (Assume that the density of gasoline is 0.680 g/cm3).

2

20. Imagine three isotopes of hydrogen. What do all three isotopes have in common? a) They all have the same number of protons b)They all have the same atomic mass b) They are all equal in terms of stability c) They all have the same number of neutrons

21. Rank the following elements in order of increasing electronegativity (lowest to highest) F, He, Li, N 22. Consider the noble gases. Why these elements rarely react with other elements? 23. The group that contain He and Ne gas in the periodic table is a) highly reactive materials b) almost non reactive gases c) less reactive metals. 24. Which of the following elements would you predict to have the largest atomic radius? a) Cs b) F c) I d) Na 25. The pressure is 6.5 atm, 2.3 mole of Br2 gas occupies 9.3 L . What is the temperature in C?

26. A sample of a gas has a pressure of 3.00 atm, a temperature of 182 K, and a volume of 15.0 L. What is the new temperature of the gas if the pressure is changed to 1.5 atm and the volume is decreased to 5.50 L?

27. A student is asked to to determine the average kinetic energy of the particles in a beaker of water … which of this should use? A) a microscope B) a thermometer C) a balance D) none of the above. 28. 15 L of a gas are stored at 15°C and 2.5 atm pressure. How many moles of gas are there?

29. For a fixed amount of a gas, the relationship between volume and temperature (P is const.) is --------proportional. 30. Robert wants to find the density of an unknown liquid. He knows the mass of his liquid is 67 grams. What other measurement must she know? A) the liquid mass in liters B) the liquid’s volume in militers. C) the liquid’s mass in cubic centimeters D) the liquid’s volume in grams. 31. When you plot a graph, which variable go along the x axis? Along y axis? 32. Do positive and positive charge attract or repeal? Negative and negative charge? Positive and negative?

3

33. Imagine you rubbed a balloon with hair and your hair become positive charged and balloon become negatively charged. Which of the following statements best explains how it is done? a) Protons are added to the hair and electrons are added to balloon b) Protons are added to hair and protons are removed from hair c) Electrons are removed from hair and protons are removed from balloon. d) Electrons are removed from hair and electrons are added to balloon. 34. What is common between Li and Na atoms? a) They have same number of protons? b) Same number of neutrons b) Same number of electrons c) Same number of valence electrons 35. Na and K are in the same group in the periodic table. Based on their locations, which of the following statement is true? a) Na is less electronegative than K b) Na has fewer electron shells than K c) Na larger ionic radius than K d) Na has a lower ionization energy than K. 36. What characteristic identifies an element? a) The number of electrons b) The number of protons c) number of neutrons d) number of electron orbitals 38. Which of the following will most likely happen to a helium – filled balloon when left in a freezer for two hours? A) its volume will increase B) no change will occur C) the balloon will explode D) the helium atoms will slow down and move closer together. 39. Draw the Lewis dot diagram for elements in period 2.

50. 10 L of gas is stored at 5°C and 1.2 atm of pressure. How many moles of gas are there?

41. For a fixed amount of a gas, the relationship between pressure and volume (T is const.) is ---------- proportional. Samantha leaves a chips bag in car during summer. She comes back to find the bag has popped. 42. Which of the following best describes why? A) T in car increased as P inside bag decreased B) T in car decreased as P inside bag increased C) T in car increased as P inside bag increased D) the gas particles inside bag grew larger and popped the bag 43. Particles of two different gases at 0°C will have a) same kinetic energy b) different average kinetic energy c) no kinetic energy d) an average kinetic energy that depends on the amount of gas. 2) When heat is added to a chemical solution, the atoms will: a) slow down b) speed up c) burn up and disappear d) reverse the reaction. 44. A sample of a gas has a pressure of 2.00 atm, a temperature of 175 K, and a volume of 10.0 L. What is the new temperature of the gas if the pressure is changed to 2.5 atm and the volume is decreased to 7.50 L?

45. What is the main difference between the Bohr model and the modern (quantum mechanical model) of the atom?

4

A) Bohr model had a nucleus with protons only and modern model with proton and neutron b) In Bohr model electrons located outside nucleus while in other model electron have a small probability of being found in nucleus. c) In Bohr model electron are not located precisely while in other model exact location of electron can be calculated. d) In Bohr model e travel along specific paths, while in modern model electron located in orbitals. 46. Robert wants to find the density of an unknown liquid. He knows the mass of his liquid is 67 grams. What other measurement must she know? A) the liquid mass in liters B) the liquid’s volume in militers. C) the liquid’s mass in cubic centimeters D) the liquid’s volume in grams 47. What causes an atom to have high ionization energy? 48. The group that contain He and Ne gas in the periodic table is a) highly reactive materials b) almost non reactive gases c) less reactive metals. 49. Which of the following elements would you predict to have the largest atomic radius? a) Cs

b) F

c) I d) Na

50. Write the noble gas configuration for titanium.

51. What type of bond most likely to hold nonmetals: a) ionic, b) covalent, c) polar covalent, d) organic

52. What type of bond is formed between atoms of carbon and hydrogen in methane (CH4)?

53. What type of bond is formed between atoms of calcium and chlorine?

54. Draw Lewis dot structure for sodium sulfide.

55. What kind of solution will conduct electricity in water, ionic or covalent?

56. How does the bonds between elements of water are formed a) sharing elements b) sharing electrons

5

c) ionic attraction d) electrostatic attraction 57. What kind of bond is formed between elements in alkali and halogens group?

58. How many grams of an unknown gas are contained in 12.5 moles at 2.50 atm of pressure and 323 K? The unknown gas has a density of 4.32 g/L. (R = 0.0821 L*atm/mol*K)

6