Acids, alkalis and salts

Acids turn litmus solution 酸使紫色石蕊试剂变

• red

• blue

• purple

Alkalis turn litmus solution 碱使紫色石蕊试剂变

• red

• blue

• purple

True or false? Acids turn phenolphthalein red

判断正误：酸使无色酚酞试剂变红

• True

• False

Alkalis turn phenolphthalein 碱使无色酚酞试剂变

• pink

• blue

• Colorless

The solution is acidic when pH value is 酸性溶液pH值

• <7

• =7

• >7

The solution is basic when pH value is 碱性溶液pH值

• <7

• =7

• >7

The solution is neutral when pH value is 中性溶液pH值

• <7

• =7

• >7

All acids contain 所有酸都含有

• H+

• OH-

• H

• OH

All alkalis contain 所有碱都含有

• H+

• OH-

• H

• OH