acidic solution

neutral solution

alkaline solution

acidic solution

neutral solution

alkaline solution

Only alkaline solutions can be tested

colorless liquid

volatility

pungent odor

Metal surface rust removal

Human gastric juice contains hydrochloric acid

Colorless, viscous oily liquid

Not easy to evaporate

water absorbency

Corrosive (dehydrating)

Strong oxidizing property (concentrated sulfuric acid)

Important chemical raw materials

Metal smelting, metal rust removal

gas desiccant

instrument

Slowly pour water along the inside of the container, stirring continuously with a glass rod to dissipate heat

red

colorless

white solid

Easily deliquescent, easily soluble in water and exothermic

caustic alkali

caustic soda

caustic soda

White powdery solid

Slightly soluble in water, solubility decreases with increasing temperature

solid

aqueous solution

The reaction between quicklime and water is CaO H2O=Ca(OH)2

blue

red

Hydrogen ion

Hydroxide ion

Acidic

alkaline

slaked lime

Too much Hcl

Potions containing alkaline substances

0∽14

pH>7

pH=7

pH<7

1. Use tweezers to take the pH test paper and place it in a white porcelain or glass piece

2. Use a glass rod to dip a drop of the liquid to be measured onto the pH test paper

3. Read the pH value against the standard color card

Do not immerse the pH test paper directly into the liquid to be measured

Do not use distilled water to wet pH test paper

Clean the glass rod before use

Crops are suitable for growing in neutral soil

When the pH value is less than 5.6, it is acid rain