Part II. MULTIPLE CHOICE

9. Moth balls (paradichlorobenzene-C6H4Cl2) are used as cockroach repellent. It is often placed inside the cabinet. If 1piece of moth ball weighs 5.0g and your mother put 3 pieces in your cabinet, how many molecules of paradichlorobenzene-C6H4Cl2 (Molar Mass = 147.00 g/mol) will be circulating inside your cabinet considering all the moth balls have sublimed?
A. 6.02 x 10 22 molecules of C6H4Cl2
B. 6.02 x 10 23 molecules of C6H4Cl2
C. 6.14 x 10 22 molecules of C6H4Cl2
D. 6.14 x 10 23 molecules of C6H4Cl2

10. Zinc is used as a corrosion – resistant coating on iron and steel. It is also an essential trace element in your diet. How many moles contain 3.50 x 1025 atoms of Zinc (Zn)?
A. 55.1 mol
B. 56.0 mol
C. 57.1 mol
D. 58. 1 mol

11. Gold is one of the coinage metals (copper, gold and silver). How many atoms of gold (Au) are in a pure gold nugget having a mass of 34.0 g?
A. 1.04 x 1023
B. 1.03 x 1024
C. 1.04 x 1025
D. 1.03 x 1026