2. Indicate the number of molecules in: a. 0.5 moles NH3
b. 1 mole of KOH

3. Indicate how many moles of compounds are in:

a. 1 g of HCl
b. 1g H2
c. 1 g CH4

4. One container contains 150 g of ethyl alcohol, C2H6O.
a. Calculate the number of moles of C2H6O
b. The number of C2H6O molecules

5. What is the centesimal composition by mass of Cu (NO3) 2?

6. A compound has the following centesimal composition by mass: Na: 43.4%, C: 11.3%, O: 45.3%. Find your formula

Data: Atomic masses: Ag = 108; N = 14; Al = 27; P = 31; O = 16; H = 1; K = 39; Cl = 35.5; C = 12;