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Acids/Bases- Sec. 3.2. Vocabulary to know:. Mixture Solute Solvent Acid Base Ion Proton Cation pH scale Strong acid Strong base. Solutions. Water is not always pure…lots of times it is part of a mixture. Mixture- Material composed of 2 or more materials.
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Acids/Bases- Sec. 3.2 • Vocabulary to know: • Mixture • Solute • Solvent • Acid • Base • Ion • Proton • Cation • pH scale • Strong acid • Strong base
Solutions • Water is not always pure…lots of times it is part of a mixture. • Mixture- • Material composed of 2 or more materials. • Ex: salt water, soda (sugar + water), etc.
Solutions • Putting salt into water creates a solution. • Solute- • Substance that is dissolved • Ex: salt • Solvent- • Substance in which the solute dissolves. • Ex: water • Water is the greatest solvent on Earth.
Why do things taste sour or bitter? • Depends on whether they have acids or bases in them! • Acids- • Taste sour (when dissolved in water) • Orange juice, tomatoes, vinegar • Bases- • Taste bitter (when dissolved in water) • Soap, ammonia, Sodium Hydroxide
Can water be an ion? • Ion- • A charged particle • Sometimes water can dissociate to form: • Hydrogen ion (H+) • And Hydroxide ion (OH-) • About 1 water molecule in 550 million.
What is an acid? • Acid- • A substance that can donate a hydrogen ion (H+) to another substance • H+ is also known as a proton • H2O can be an acid or a base
What is a base? • Base- • A substance that can accept a hydrogen ion (H+) from another substance • Hydroxide ion (OH-) is formed • It can accept H+
Characteristics of acids… • Taste sour • Produce a burning/prickling feeling on skin • Change color of some compounds • Red on litmus paper • React with most metals to form a gas
Characteristics of bases… • Taste bitter • Feel slippery • They react with acidic molecules called fatty acids • Mix NaOH with fatty acids make soap • Some can burn your skin like an acid! • Changes color of some compounds • Blue on litmus paper
Are some acids and bases stronger than others? • Oh Yeah! • You can drink and eat some weak acids and bases • Orange juice, tomatoes, salt water, etc. • Drinking or eating strong acids or bases can make you very sick
How do we measure strength? • pH scale- • Measures the concentration of H+ or OH- • Strong acid = Lot’s of H+ in the solution • 0 = strong acid • Strong base = Lot’s of OH- in the solution • 14 = strong base • Water is a weak acid AND a weak base… it is neutral • 7 = neutral