Acids, Bases, and Salts

Properties of acids: - contain the hydronium ion, H 3 O + - react with metals to form hydrogen gas, H 2 - taste sour - have pH values less than 7 - corrosive to body tissue - react with bases to form water and a salt

Properties of bases: - contain the hydroxide ion, OH - - feel slippery - taste bitter - have pH values greater than 7 - dissolve grease - react with acids to form water and a salt

Indicators:substances that change color in the presence of an acid or a base examples: red and blue litmus paper bromothymol blue

pH Scale

Strength of Acids, Bases Depends on how completely they turn into ions (“dissociate”) when dissolved in water HCl in water: Every HCl dissociates and creates a hydronium ion Strong acid

Acetic acid (vinegar) in water: acetic acid CH 3 COOH CH 3 COO - H3O+H3O+ H2OH2O Most acetic acid molecules do not dissociate into ions; most stay as molecules Weak acid

Sodium hydroxide ( NaOH ) in water: Complete dissociation into Na + and OH - ions Strong base

Ammonium hydroxide ( NH 4 OH ) in water: Most ammonia molecules do not dissociate into ions; most stay as molecules Weak base

Strong Acid Weak Acid Hydrochloric ( HCl ) Sulfuric ( H 2 SO 4 ) Nitric ( HNO 3 ) Strong Base Sodium hydroxide ( NaOH ) Potassium hydroxide ( KOH ) Acetic ( CH 3 COOH ) Citric ( C 6 H 8 O 7 ) Weak Base Ammonia ( NH 4 OH ) Sodium carbonate ( Na 2 CO 3 ) dissociates completelydoes not dissociate completely

Neutralization Reactions acid + base water + salt HCl + NaOHex.H 2 O + NaCl double displacement rxn. H 2 SO 4 + KOHex. H 2 O + K 2 SO 4

Neutralization Reactions acid + base water + salt HCl + NaOHex.H 2 O + NaCl double displacement rxn. H 2 SO 4 + KOHex. H 2 O + K 2 SO 4 22 what’s wrong with this?not balanced

Neutralization Reactions acid + base water + salt HCl + NaOHex.H 2 O + NaCl double displacement rxn. H 2 SO 4 + KOHex. H 2 O + K 2 SO 4 22 balanced

H 2 SO 4 + NaOH ex.Predict the products of the following neutralization reaction (hint: one of the products is always water). Write the proper chemical formula of the products, and then balance the equation. H2OH2O+sodium sulfate chemical formula?

H 2 SO 4 + NaOH ex.Predict the products of the following neutralization reaction (hint: one of the products is always water). Write the proper chemical formula of the products, and then balance the equation. H2OH2O+ criss-cross method: NaSO 4 oxidation number: Na SO 4 sodium sulfate chemical formula?

ex.Predict the products of the following neutralization reaction (hint: one of the products is always water). Write the proper chemical formula of the products, and then balance the equation. H2OH2O+ criss-cross method: NaSO 4 oxidation number: Na 2 SO 4 now balance the equation 22H 2 SO 4 + NaOH

HNO 3 + Ba(OH) 2 ex.Predict the products of the following neutralization reaction (hint: one of the products is always water). Write the proper chemical formula of the products, and then balance the equation. H2OH2O+barium nitrate chemical formula? criss-cross method: BaNO 3 oxidation number: Ba NO 3

HNO 3 + Ba(OH) 2 ex.Predict the products of the following neutralization reaction (hint: one of the products is always water). Write the proper chemical formula of the products, and then balance the equation. H2OH2O+ criss-cross method: BaNO 3 oxidation number: Ba ( NO 3 ) 2 now balance the equation 22