lab: investigating ph of various household products objective is to determine the ph of common...
TRANSCRIPT
LAB: INVESTIGATING PH OF VARIOUS HOUSEHOLD PRODUCTS
O B J E C T I V E I S T O D E T E R M I N E T H E P H O F C O M M O N H O U S E H O L D S U B S T A N C E S A N D U S E T H I S I N F O R M A T I O N T O I D E N T I F Y T H E S U B S T A N C E A S A N A C I D I C , B A S I C O R N E U T R A L S O L U T I O N .
VOCABULARY BUILDING: BE SURE THAT YOU CAN DEFINE THESE TERMS BEFORE DOING THE LAB
Solvent
Solute
Solution
Aqueous
Dissociate
Hydrogen ion
Hydroxide ion
Neutral Solution
Acidic Solution
Basic Solution
WATER IN A GLASSHOW DO THE MOLECULES APPEAR?
Above is a diagram of the way in water molecules can look in the glass to the left. The water molecules breaks into ions, hydroxide and hydrogen.
Diagram below shows Water molecules with 2 hydrogenAtoms and 1 oxygen atom
Need an “indicator” which is something that detects the presence of a certain substance
MATERIALS
Paper Indicators to determine if solution is acid/base:
1. pH paper *indicates the presence and amount of H+
2. litmus red paper3. litmus blue paper
Above you can see the three types of papers. The pH paper is the light yellow coloredpaper. The red paper is red and the blue paper is blue. A beaker of distilled water is available to clean the stirring rod after each application of a substance on the paper. Preventing contamination of solutions is very important.
Solution Guess Acid Base Neutral
Milk x
Vinegar x
Egg white
x
Orange Juice
x
Ammonia x
Unknown #1
x
Unknown#2
x
Data Table 2 indicates the type of solution for a given householdproduct
Unknown #1 – Baking Soda WaterUnknown #2 – Lemon Juice
Solution pH Paper Litmus Red
Litmus Blue
Milk 6-7 Red Red
Vinegar 1-2 Red Red
Egg white 7-8 Blue Blue
Orange Juice
4 Red Red
Ammonia 9 Blue Blue
Unknown #1
8-9 Blue Blue
Unknown #2
1-2 Red Red
Data Table 1: Color of Paper Indicator With a Given Household Product
PART B: NEUTRALIZATION REACTION
Phenolphtalein is another indicator. It will go from colorless to pink if the solution becomes basic. What does that mean to say a solution is basic? In this part, you willuse this indicator to demonstrate a neutralization reaction.