Flashback Problems

6. How much energy in kJ does a 120 V appliance drawing 2.5 A current use in 6 hours?

This question is out of place. We will cover it in the next section.

7. If eight 10 W resistors are connected in parallel to a 120 V source, how much current will be drawn by each resistor? Draw out this situation before you tackle the problem.

I=V/R = 120 V /10 W = 12 A. Recall that voltage is constant in parallel.

8. What two families of the periodic table form compounds involving the +1 and +2 ions, respectively?

Alkali metals (first column) form +1 ions

Alkaline earth metals (2nd column) form +2 ions

9. Specific heat is a characteristic physical property.

a. Give another physical characteristic property for water.

Density, or boiling point or melting point

b. Give a characteristic chemical property of water.

2 moles of water can react to produce hydrogen and oxygen in a 2:1 ratio.