Module 5 Intro

1. Module 5 Intro

1.13. Page 3

Lesson 2

Module 5—Acids and Bases

Read

Calculating pOH

Read “pOH and Hydroxide Ion Concentration” on page 243 in your textbook. To practise calculations involving hydroxide-ion concentration and pOH, attempt Communication examples 3 and 4 on page 243.

Example 5

Calculate the pOH of a solution that has a hydroxide-ion concentration of 4.52 × 10−7 mol/L.

A photograph shows the display screen of a calculator. The first line reads negative sign log bracket four decimal five two E negative seven bracket. The second line reads six decimal three four four eight six one five six five.

Example 6

A solution has a pOH of 0.81. Determine the hydroxide-ion concentration.

A photograph shows the display screen of a calculator. The first line reads ten caret negative sign zero decimal eight one. The second line reads decimal one five four eight eight one six six one nine.

Self-Check

SC 5. Calculate the pOH of a solution that has a hydroxide-ion concentration of 3 × 10−8 mol/L.

SC 6. A solution has a pOH of 11.925. Determine the hydroxide-ion concentration.

SC 7. A solution has a pOH of 13.0. Describe the empirical properties of this solution.

Check your work.

Self-Check Answers

SC 5.

A photograph shows the display for a calculator. The first line reads negative sign log bracket three E negative eight bracket. The second line reads seven decimal five two two eight seven eight seven four five.

SC 6.

A photograph of the display for a calculator the first line reads ten caret sign negative sign eleven decimal nine two five. The second line reads one decimal one eight eight five zero two two three E negative twelve.

SC 7. A solution with a pOH of 13.0 will be very acidic in nature. If a pOH of 1.0 is very basic, the other end of the scale will be acidic. The properties will be consistent with those of an acidic solution—sour taste, reacts with metals, and turns blue litmus red.