1. Clicker #1
Balance the following equation in standard form and determine the sum of the coefficients:
C2H5OH + O2 → CO2 + H2O
A) 4
B) 5
C) 8
D) 9
E) 10

2. Clicker #2
How many of the following statements are true about balanced chemical equations?
I. The same numbers of atoms of each element must be present on the reactant side and on the product side.
II. The sum of the coefficients on the reactant side is always equal to the sum of the coefficients on the product side.
III. Only whole numbers can be used to balance a chemical equation.
IV. Subscripts in the formulas can be changed to balance an equation.
A) 0
B) 1
C) 2
D) 3
E) 4

3. Clicker #3 What are the possible products? AgNO3(aq) + KCl(aq) → ?
A) AgCl and KNO3
B) AgNO3 and KCl
C) AgK and NO3Cl
D) Any of the above could be the products.

4. Clicker #4 So what must be true about KNO3?
A) KNO3 is aqueous (soluble) in all three reactions.
B) KNO3 is the solid in reactions 1 and 2 but not reaction 3.
C) KNO3 is the solid in reaction 1 but not in reactions 2 and 3.
D) KNO3 is the solid in reaction 2 but not in reactions 1 and 3
E) KNO3 is the solid in reaction 3 but not in reactions 1 and 2.