Exam 1 Review - Practice questions for exam 1 for Chem 120 class. PDF

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Practice questions for exam 1 for Chem 120 class. ...

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Exam 1 Review Chapter 1,2 and 3 1. Use the prefix multipliers to express each of the following measurements without any exponents. a. 2.6 x 10-9 m b. 14 x 10-6 s c. 1.2 x 103 g d. 7.9 x 106 L

2. The wind chill in Chicago reached -60°F during the blizzard of 1978. Convert the temperature to °C and K.

3. Sodium hypochlorite (bleach when dissolved in H 2O) has a density of 1.11 g/cm 3. a. What is the mass in g of 512 mL of this liquid?

b. What is the volume in L of 5.1 kg of this liquid?

4. Perform each of the following conversions. a. 132 mm to in

b. 1.56 kg to g

c. 712 cm to in

d. 12.6 L to qt

5. A Canadian hybrid automobile has a gas mileage of 18 km/L. What is the gas mileage in mi/gal?

6. A new chemistry building contains General Chemistry labs that has an area of 432 m 2. What is the area in: a. km2

b. dm2

c. cm2

7. How many significant figures does each number have? a. 0.0637 b. 7.235 c. 5860 d. 7.3 x 103 e. 65.69 f. 4.039 g. 109.0 h. 1090 i. .1090

8. Perform the following calculations with correct significant figures a. 7.00 x 50.0 + 20.0 x 50.0 + (2.00 x 10 1)

b. 0.2596 x (1.00 + 103) / [ 6.207 x (1.64)3]

c. [10 x 50.0 + 47.9] / (4.000 x 10 3)

9. The density of chromium is 7.19 g/cm 3. What is the volume (in cubic inches) of 4.5 lb. of chromium?

10. A Chevy Suburban K1500 XLT has an EPA gas mileage rating of 16 mi/gal in the city. How many kilometers can the truck travel on 12 liters of gasoline?

11. Two samples of carbon dioxide are decomposed into their constituent elements. One of the samples produces 23.8 g of oxygen and 8.9 g of carbon. The other produces 19.5 g of oxygen and 7.3 g of carbon. Show the results are consistent with the law of definite proportions.

12. List the three main components of the atom

13. How many protons, neutrons, and electrons are present in an atom of 3517Cl?

14. A neutron is positively charged. True or false 15. Protons are negatively charged. True or false 16. Electrons are negatively charged. True or false 17. What is the atomic number, mass number, and symbol for the carbon isotope with 7 neutrons?

18. For each of the following ions determine the number of: Protons a. b. c. d.

Neutrons

Electrons

O2Fe3+ BrCr3+

19. Magnesium has three naturally occurring isotopes with masses of 23.99 amu, 24.99 amu, and 25.98 amu and natural abundances of 78.99%, 10.00%, and 11.01% respectively. Calculate the atomic mass of magnesium.

20. Write the isotopic symbols for the following isotopes. a. The aluminum isotope with 14 neutrons

b. The sodium isotope with 12 neutron

c. The hydrogen isotope with 1 neutron

d. The iodine isotope with 74 neutrons

21. A pure platinum wedding ring contains 3.60 x 1022 platinum atoms. How many moles of platinum atoms does it contain?

22. True or False a. The speed of light is 3.0 x 10 -8 m/s b. Planks constant has units of J*min c. Wavelength is the distance between two analogous points. d. Lambda (λ) is the symbol to represent frequency.

23. What is the height of a wave called?

24. A barcode scanner emits a red light that has a frequency of 4.62 x 10 14 s-1. Calculate the wavelength of the red light in nm.

25. A nitrogen gas laser pulse with a wavelength of 337 nm contains 3.83 mJ of energy. How many photons does it contain?

26. A football stadium displayed scores using brilliant lasers emitting a green light with a wavelength of 515 nm. Calculate the frequency of the light.

27. Each of the following sets of quantum numbers is supposed to specify an orbital. However, each set contains one quantum number that is not allowed. Replace the quantum number that is not allowed with the one that is allowed. a. n = 3; l = 3; ml = +2 b. n = 2; l = 1; ml = -2 c. n = 1; l = 1; ml = 0

28. The energy required to dislodge electrons from sodium metal via the photoelectric effect is 275 kJ/mol. What wavelength in nm of light has sufficient energy per photon to dislodge an electron from the surface of sodium?

29. Determine the wavelength of light absorbed when an electron in a hydrogen atom makes a transition from an orbital in n = 2 to an orbital in n = 7.

30. Determine whether each of the following transitions, in the helium atom corresponds to adsorption or emission. a. n = 2 → n = 1 b. n = 1 → n = 3 c. n = 4 → n = 2 31. Which electron is, on average closer to the nucleus: An electron in the 5s orbital?

An electron in the 4d orbital

32. How many electrons can have the following quantum numbers? a. n = 3; l = 1; ml = 0 b. n = 5; l = 3 c. n = 2; l = 1; ml = -1; ms = -

1 2

d. n = 4; l = 2 33. Which electron is, on average closer to the nucleus: An electron in the 2s orbital?

An electron in the 4s orbital?

34. Give the condensed electron configuration for the following atoms or ions. a. Y b. Ba2+ c. As d. Fe2+ e. Eu f.

Cr

g. S2h. Ti2+ i. Ti4+ 35. Calculate the frequency and the energy of a photon at each of the following wavelengths. a. 750 nm

b. 503 nm

36. A laser pulse with wavelength 532 nm contains 4.67 mJ of energy. How many photons are in the laser pulse?...