Acids, Bases & pH Scale Bell Ringer

When you place blue litmus paper into an unknow solution, the blue litmus paper turns red. Which of the following indicates the most logical conclusion?

• The substance has a pH of 7.

• The substance has a pH of 14.

• The substance is an acid

• The substance is a base

As an acidic solution is added to a basic solution, the pH of the basic solution

• increases

• decreases

• remains the same

• multiplies

What range of values on the pH scale represent solutions with a higher ration of hydroxide (OH-) ions?

• 0-14

• below 6

• above 7

• 7

Which statement correctly describes a solution with a pH of 9?

• It has a higher concentration of H₃O+ than OH^- and causes litmus to turn blue

• It has a higher concentration of H₃O+ than OH^- and causes phenolphtalien to turn pink.

• It has a higher concentration of OH^- than H₃O⁺ and causes litmus to turn blue

• It has a higher concentration of OH^- than H₃O⁺ and causes phenolphtalien to turn colorless.

Which of the following statements is correct?

• Blue litmus paper turns red when placed in a base.
• Red litmus paper turns blue when placed in a base.
• Blue litmus paper stays blue when placed in an acid.
• Red litmus paper stays red when placed in a base.

A solution has a pH of 7.0.

What would happen to the pH if H₃O⁺ ions were added?

• pH would go down

• pH would go up

• pH would stay the same

• None of these

Which one of the following is NOT a property of basic solutions?

• Feels soapy/slippery

• Tastes sour

• Conducts electricity

• Turns red litmus paper blue

If an acid is combined with a base of equal strength, the result will most likely be

• a neutral solution.
• a stronger acid.
• impossible to tell without testing the pH.
• a stronger base

Water has a neutral because

• it has more H+ ions than OH-

• it has more OH- ions than H+

• it does not produce any ions

• it has an equal amount of H+ and OH- in solution

When H⁺ concentration is greater than OH^- concentration, the solution is

• basic

• neutral

• acidic

• alkaline