T a k e H o m e : C h e m i s t r y | 1

Prepared by: Engr. Ricardo A. Banal Jr. ricbanal@gmail.com

1. Who revised the atomic theory by replacing the hard, indestructible spheres imagined by Dalton and proposed the “raisin bread model” of the atom? a. Pierre Curie b. Robert Andrews Millikan c. Joseph John Thomson d. Humphrey Davy

2. The number of __________ in an

atom defines the isotopes of an element. a. neutrons b. protons c. electrons d. protons and neutrons

3. The elements with similar

properties are placed in columns of the periodic table. These columns are commonly called _____. a. Periods b. Groups c. Families d. Groups or families

4. What principle states about the

fundamental limitation that, for a particle as small as the electron, one cannot know exactly where it is and at the same time know its energy how it is moving? a. Autbau principle b. Uncertainty principle c. Pauli exclusion principle d. Kinetic molecular theory

5. What principle states that the

electrons fill the orbitals, one at a time, starting with the lowest orbital then proceeding to the one with higher energy? a. Autbau principle b. Uncertainty principle c. Pauli exclusion principle d. Kinetic molecular theory

6. What describes how the

electrons and distributed among the orbitals? a. Electronegativity of the

element b. Electron configuration of an

atom c. Energy state of the atom d. Pauli exclusion principle

7. The _______ of the atom describes

the atom as having a nucleus at the center around which electrons move? a. spin number b. quantum mechanical model c. quantum number d. azimuthal number

8. How much carbon dioxide is present in dry air? a. 0.003% b. 0.03% c. 0.3% d. 3%

9. When the solvent of the

solution is water, it is a/an _____ solution. a. wet b. liquid c. aqueous d. fluid

10. Who proposed the pH scale in

1909? a. Albert Einstein b. J. Williard Gibbs c. Henri Hess d. Soren Sorensen

11. Compounds that contain

halogens are called __________. a. Amines b. Halides c. Ethers d. Aldehydes

12. An element maybe defined as a

substance with all atoms of which have the same __________. a. Number of neutrons b. Radioactivity c. Atomic weight d. Atomic number

13. What percent of the human

body is carbon? a. 22% b. 20% c. 18% d. 16%

14. What refers to a chemical

formula that shows how atoms are bonded to one another in a molecule? a. Molecular formula b. Structural formula c. Standard formula d. Bonding formula

15. What is a general term that

refers to an allowed energy state for an electron in the atom? a. Quantum orbital level b. Quantum energy level c. Orbital d. Quantum Theory

16. Calculate the moles of

Magnesium (Mg) present in 93.5 g of Mg? (Mg atomic mass = 24.31g) a. 3.85 moles b. 4.15 moles c. 5.38 moles d. 3.35 moles

17. How many number of atoms are

there in 1.32 x 10^3 g of Lead (Pb)? Pb atomic mass is 207.7g. a. 3.84 x 10^23 atoms b. 4.38 x 10^23 atoms c. 3.84 x 10^24 atoms d. 4.38 x 10^24 atoms

18. Given 16.7 moles of gold (Au),

how many grams of Au are there? Atomic mass of Au is 197.0g. a. 3.51 x 10^3 g b. 3.29 x 10^3 g c. 2.39 x 10^3 g d. 3.76 x 10^3 g

19. Calculate for the number of

molecules of ethane (C2H6) present in 0.431 g of C2H6. (C atomic mass = 12.01g; H atomic mass = 1.008 g) a. 8.63 x 10^21 C2H6

molecules b. 8.75 x 10^21 C2H6

molecules c. 7.69 x 10^21 C2H6

molecules d. 9.13 x 10^21 C2H6

molecules

20. The atomic masses of carbon, hydrogen, and oxygen are 12.01g, 1.008g, and 16g respectively. Calculate the molarity of a 90-mL ethanol (C2H5OH) solution which contains 2.15 g of ethanol. a. 0.52 M b. 0.25 M c. 0.61 M d. 0.44 M

21. Solve for the volume occupied

by 3.12 moles of nitric oxide (NO) which exerts 5.43 atm of pressure at a temperature of 82oC. a. 16.75 L b. 13.84 L c. 15.76 L d. 16.48 L

22. Calculate the volume occupied

by 50.6 g of HCl at STP. H = 1.008 amu and Cl = 35.45 amu. a. 83.2 L b. 31.1 L c. 27.4 L d. 1.38 L

23. Assuming there is no change in

volume, determine the molarity of the acid solution if a 3.12-L sample of hydrogen chloride gas at 2.57 atm and 27.5oC, which is completely dissolved in a 700 mL of water to form hydrochloric acid solution.

T a k e H o m e : C h e m i s t r y | 2

Prepared by: Engr. Ricardo A. Banal Jr. ricbanal@gmail.com

a. 0.644 M b. 0.000464 M c. 0.464 M d. 0.0464 M

24. Calculate the number of

molecules of oxygen gas present in 1.5 L of air at STP. Assuming that air contains 31% O2, 67% N2 and 2% Ar, all by volume. a. 1.87 x 10^23 molecules b. 4.18 x 10^24 molecules c. 2.81 x 10^23 molecules d. 1.25 x 10^22 molecules

25. Which of the following is the

molar mass of the gas at 752 torr and 41oC? Ten grams of a gas occupy a volume of 5.12 L. a. 51 g/mol b. 1.96 g/mol c. 149 g/mol d. 1144 g/mol

26. Calculate the mass of a piece of

platinum metal with a density of 34.1 g/cm3 and has a volume of 5.2 cm3. a. 17.732 g b. 1773.2 g c. 177.32 g d. 1.7732 g

27. Bromine (Br) and Silver has

atomic masses of 79.90g and 107.9g, respectively. In a certain experiment, a sample of 0.3320g of an ionic compound containing the bromide ion (BrI) is dissolved in water and treated with an excess of AgNO3 if the mass of the AgBr precipitate that forms is 0.734 g, calculate the percent by mass of Br in the original compound? a. 42.55 % b. 49.70 % c. 84.10 % d. 94.07 %

28. The atomic masses of carbon,

hydrogen, and oxygen are 12.07g, 1.008g and 16.00g respectively. Calculate the number of C atoms present in 84.5 g of isopropanol (rubbing alcohol), C3H8O? a. 2.88 x 1024 C atoms b. 3.72 x 1024 C atoms c. 2.54 x 1024 C atoms d. 2.00 x 1024 C atoms

29. How many water molecules are

present in 5.34 mL of water at a temperature of 4oC, which the density of water at this temperature is 1.00 g/mL? Atomic masses of H and O are 1.008 g and 16.00 g respectively.

a. 1.84 x 10^23 molecules b. 1.78 x 10^23 molecules c. 1.74 x 10^23 molecules d. 1.87 x 10^23 molecules

30. Zinc (Zn) atom has atomic mass

of 65.39. Calculate the number of atoms present in 4.22 g of zinc (Zn). a. 3.75 x 10^22 Zn atoms b. 3.93 x 10^22 Zn atoms c. 3.89 x 10^22 Zn atoms d. 4.04 x 10^22 Zn atoms