Question

1. Which of these reactions are balanced correctly?
a. C3H6 + 3O2→ 3CO2 + 3H2O
b. C2H6 + 3O2→ 2CO2 + 3H2O
c. C4H8 + 6O2→ 4CO2 + 4H2O
d. 2C6H10 + 17O2→ 12CO2 + 10H2O

2. In the reaction A + B → CD, the mass of CD is 100 g and the mass of A is 75 g. What is the mass of B?
a. 175 g
b. 100 g
c. 25 g
d. 0 g

3. In the equation, 2Al (s) + 3Cl2 (g) → 2AlCl3 (s), the large number “3” in front of the Cl2 indicates:
the number of chlorine atoms needed to balance the equation
the number of chloride molecules needed to balance the equation
the number of moles of chlorine atoms needed

Answer 1

1c, 2c, 3c