3.1 Acids and Alkalis

• What color does litmus paper turn in alkaline conditions?

  Blue
• Acids have a pH less than 7
• Acids have a pH less than 7, indicating they are acidic
• What color does litmus paper turn in alkaline conditions?

  Blue
• What is the taste of alkalis?

  Bitter
• What ions do strong alkalis produce in water?

  Hydroxide ions (OH-)
• What reaction occurs when acids interact with metals?

  Hydrogen gas production
• What happens to litmus paper when exposed to acids?

  Turns red
• What is the pH range for acids?

  Less than 7
• What is the pH range for alkalis?

  Greater than 7
• Alkalis produce hydrogen gas when reacted with metals.

  False
• What is considered a neutral pH on the pH scale?

  7
• Match the indicator with its color in acidic conditions:

  Litmus paper ↔️ Red

  Phenolphthalein ↔️ Colorless

  Universal indicator ↔️ Red/orange
• Indicators undergo a chemical reaction to change color based on pH.


  True
• When HCl reacts with NaOH, the products are NaCl and H2O.


  True
• During neutralization, acidic and alkaline properties are neutralized.


  True
• Acids have a pH less than 7, while alkalis have a pH greater than 7.

  True
• Acids are used to lower pH in swimming pools and aquariums.


  True
• What gas is produced when acids react with metals?

  Hydrogen gas
• What is the pH of a neutral substance?

  7
• Strong acids have a high pH and low conductivity.

  False
• Each whole number on the pH scale represents a tenfold difference in hydrogen ion concentration.

  True
• Match the pH range with its category:

  0 to < 7 ↔️ Acidic

  7 ↔️ Neutral

  > 7 to 14 ↔️ Alkaline
• Indicators change color at different pH values.


  True
• Alkalis have a pH greater than 7.


  True
• Acids have a bitter taste.

  False
• Alkalis have a pH greater than 7
• Acids turn litmus paper red
• Weak acids and weak alkalis only partially dissociate
• Alkalis have a pH greater than 7 and a bitter
• Alkalis have a pH greater than 7
• Acids have a sour taste
• Alkalis have a bitter taste
• Match the type of acid/alkali with its ion concentration:

  Strong acid ↔️ High concentration of H+ ions

  Weak acid ↔️ Low concentration of H+ ions

  Strong alkali ↔️ High concentration of OH- ions

  Weak alkali ↔️ Low concentration of OH- ions
• Weak acids have a very low pH.

  False
• Lemon juice, with a pH of 2, is an example of an acidic
• Litmus paper turns blue in alkaline conditions
• What two products are formed in a neutralization reaction?

  Salt and water
• What are the pH values of acids and alkalis in a neutralization reaction?

  Less than 7 and greater than 7
• A neutralization reaction occurs when an acid and an alkali react to form a salt and water