David Lee (56)Naomi Park

Julia GregoryTaylor Seo

Experiment 20A- Introduction to Acids and Bases

Abstract

The purpose of this experiment was to distinguish the unknown solutions and household products whether it’s acidic or basic by using various types of pH indicators. Throughout the experiment, we could see the unknown solutions that are acidic reacted differently than the basic solution due to the different characteristic of base and acid.

Data and Observations

Unknown Solutions

Unknown Solutions

Chemical Indicators MagnesiumMetalPhenolphthalei

nMethyl Orange Blue Litmus Red Litmus

A Pink Yellow Blue Blue No bubbleB Clear Red Red Red BubbleC Clear Red Red Red BubbleD Pink Yellow Blue Blue No bubbleE Clear Red Red Red BubbleF Pink Yellow Blue Blue No bubble

Household Products

HouseholdProducts

Chemical Indicators MagnesiumMetalPhenolphthalei

nMethyl Orange

Blue Litmus Red Litmus

Vinegar Clear Red Red Red BubbleEasy Off Pink Yellow Blue Blue No bubble

Ammonia Pink Yellow Blue Blue No bubble7-Up Clear Red Red Red Bubble

Lemon Juice Clear Red Red Red BubbleMilk of

MagnesiaPink Yellow Blue Blue Bubble

Analysis

1) Materials and Procedures- Refer to “Heath Chemistry- Laboratory Experiments” p.230~231

2) Questions:

1) A) Group #1: A,D,F Group #2: B,C,Eb) Group #1 are bases and group #2 are acids

2) Acid: combined with phenolphthalein, results in a clear substance. combined with methyl orange, results in a red substance. combined with blue litmus, results in a red substance. combined with red litmus, results in a red substance. combined with magnesium metal, and bubbles are formed

Base: combined with phenolphthalein, results in a pink substance.combined with methyl orange, results in a yellow substance.combined with blue litmus, results in a blue substance.combined with red litmus, results in a blue substance.combined with magnesium metal, and no bubbles are formed

3) Vinegar: acid Easy Off oven cleaner: base Ammonia: base 7-up: acid Lemon juice: acid Milk of Magnesia: base

4) Household acids that are mentioned in this experiment are either drinks or used in cooking. On the other hand, the household bases mentioned here are used for cleaning.

Follow-up Questions

1) a)

b) When a compound consists of hydroxide or takes in H+ ions, it is considered basic. On the other hand, when a compound consists of H, it is considered acidic.2)

b) Every household product with its active ingredient’s chemical formula having H+ ion(s) is an acid. Every household product with its active ingredient’s chemical formula having OH- ion(s) is a base.

3) a) The Arrhenius definition of an acid is a substance that when dissolved in water increases the concentration of hydrogen ion, H+(aq). A base is a substance that when added to water increases the concentration of hydroxide ion, OH-(aq).b) The Arrhenius definitions support my conceptual definitions under the concept that acids gives off H+ ions when they dissolve and bases gives of OH- ions when they dissolve.

4) a) Chemical Indicators Magnesium

MetalPhenolphthalein Methyl Orange Blue Litmus Red LitmusAcid Rain Clear Red Red Red Bubble

b) H+ ionc) H2SO4 and HNO3

Solution Chemical Formula Acid/BaseA NaOH BaseB HCl AcidC HNO3 AcidD Ca(OH)2 BaseE H2SO4 AcidF KOH Base

Household Products Chemical Formula Acid/BaseVinegar HC2H3O2 Acid

Lemon Juice H3C6H5O7 AcidEasy-Off NaOH Base

Ammonia NH4OH BaseMilk of Magnesia Mg(OH)2 Base

7-Up H2CO3 Acid

Source of Error

1) The glass square might not been cleaned completely2) The medicine droppers might not been cleansed completely3) Because of the fact that most of unknown solutions were clear, the person

can be confused which solution is which.

Conclusion

When a compound consists of hydroxide or takes in H+ ion(s), it is considered basic. On the other hand, when a compound consists of H, it is considered acidic. Due to the fact, the solution A,D,F in part 1 are bases when the solution B,C,E are acids.