SCIENCE 9
MODULE 7 DAY 3
Let’s Try (Evaluation)
DIRECTION. Read the following questions carefully and choose the letter of the best answer.
1. Which statement is correct regarding the molecule of water (H2O)?
A. One mole of H2O contains
18.06x10²³ particles.
B. One mole of H2O is equal to twice
its molar mass.
C. One mole of H2O contains
6.02x10²³ particles.
2. How many particles are there in one mole of any kind of substance?
A. 3.01 x 10²³ B. 6.02x10 ²³
C. 3.01 x 10 D. 6.02x10 ²
3. What is the representative particle of ionic compound?
A. Atom B. ion
C. molecule D. formula unit
4. Calcium carbonate (CaCO3, Molar Mass = 100.09 g/mole) is an antacid used to neutralize extra acid in the stomach. Lorie is prescribed by the doctor to take 250-mg tablet of CaCO3 three times a day. How many moles of CaCO3 will Lorie consume for 3 days?
A. 0.0252 moles
B. 0.0225 moles
C. 0.0242 moles
D. 0.0235 moles
5. Why is mole concept important?
A. It is useful when converting between
grams and atoms or molecules.
B. It gives us a convenient way to
express large numbers.
C. It can be applied to any type of
particle representative.
D. All of the above.
6. Which of the following could be an empirical formula?
A. CH2O B. H2O2
C. N2O4 D. C6H12O6
7. A certain substance is analyzed and found to contain the following weight
percentages: 36.84% nitrogen (N) and 63.16% oxygen (O). Determine the empirical formula of this compound. (Atomic wts: N = 14.0, O = 16.0)
A. N3O2 B. NO2
C. N2O D. N2O3
8. If the empirical formula of the compounds is CH2O and its molecular mass is 181 amu, what is its molecular formula?
A. C6H12O6 B. C12H22O11
C. C2H4O6 D. CHO
9. What is the molecular mass of Aspirin, C9H8O4 ?
A. 120.4 amu B. 180.17 amu
C. 176.17 amu D. 142.50 amu
10. What is the percentage composition of Oxygen in a table sugar, C12H22O11?
A. 27.84 % B. 58.21 %
C. 51.41 % D. 46.90 %

Please Answer Properly!