Section 4 – pg 274 Acids and Bases in Solution Chapter 7 Section 4 – pg 274 Acids and Bases in Solution

Strong Acid + Strong Base = Neutral Pg 274 Hydrochloric acid + Sodium hydroxide = Sodium Chloride + Water HCl + NaOH = NaCl + H2O Strong Acid + Strong Base = Neutral

Pg 274 - 275 Acids in Solution Acids produce one or more hydrogen ions and a negative ion in solution of water Hydrogen ions: an atom of hydrogen that has lost its electron Hydrogen ions are the key to the reactions of acids

Pg 275 Bases in Solution Many bases are made of positive ions combined w/ hydroxide ions Hydroxide ions: a negative ion made of oxygen and hydrogen When bases dissolve in water, the positive ions and hydroxide ions separate A base produces hydroxide ions These ions are responsible for the bitter taste and slippery feeling

Strength of Acids and Bases Pg 276 Strength of Acids and Bases Acids and bases may be strong or weak Strength refers to how well an acid or base produces ions in water With a weak acid, very few ions form in solution At the same concentration, a strong acid produces more hydrogen ions than a weak acid does

Pg 276 A strong base produces more hydroxide ions than does an equal concentration of weak base

Pg 276 Measuring pH pH Scale: a range of values from 0 – 14 that expresses the concentration of hydrogen ions in a solution pH lower than 7 is acidic pH higher than 7 is basic pH is 7 than neutral

Pg 277 A low pH indicates that the concentration of hydrogen ions is great. In contrast, a high pH indicates that the concentration of hydrogen ions is low You can find the pH of a solution using indicators pH paper turns a different color for each pH value pH meter is an electronic device that makes rapid, accurate pH measurements

Pg 278 Acid – Base reactions A reaction between an acid and a base is called neutralization Kind of like adding a negative and a positive, they cancel out

Pg 278 Reactants After neutralization, an acid-base mixture is less acidic or basic than either of the individual starting solutions The pH depends on the identities, the volumes, and the concentrations of the reactants Kinda like averaging them out Lemon juice (2) + Soap (10) = 6 Slightly Acidic

Pg 279 Products Salt: any ionic compounds that can be made from the neutralization of an acid with a base Made from the positive ion of a base and the negative ion of a acid In a neutralization reaction, an acid reacts with a base to produce a salt and water

Chapter 7 Section 4 Homework – pg 279

1A. Which element is found in all the acids described in this section?

1B. What kinds of ions do acids and bases form in water?

1C. What ions will the acid NHO3 form when dissolved in water?

2A. What does a substance’s pH tell you?

2B. If a solution has a pH of 6, would the solution contain more or fewer hydrogen ions than an equal volume of solution with a pH of 3?

2C. Would a dilute solution of HCl also be weak? Explain.

3A. What are the reactants of a neutralization reaction?

3B. What happens in a neutralization reaction?

3C. What acid reacts with KOH to produce the salt KCl 3C. What acid reacts with KOH to produce the salt KCl? KOH + ____ = KCl + H2O