Lab Activity 1-pH Determination
I. Objectives
- To determine the pH level of the given sample solutions
- To classify the samples as acidic, basic, or neutral based on the pH value.
- To understand how pH paper and universal indicator works.
II. Introduction
- The potential of Hydrogen or pH is a scale used to measure the acidity or basicity
of liquid solutions. This translates the values of the concentration of the hydrogen
ion. A solution with a pH less than 7 is considered acidic. A solution with a pH
greater than 7 is considered basic or alkaline. Solutions are considered neutral if
the pH level is 7. The pH of a solution is measured using pH indicators. The pH
indicators change color when in contact with acidic, basic, or neutral solutions.
III. Materials and Equipment
Materials Vegetable & House Hold Acids and Bases Salt in Water
fruit juices items in the Lab
pH color chart Lemon juice Common salt 0.1M HCl KCl
pH paper strip Tomato juice Baking soda 0.001M NaOH NaHCO3
Dropper Orange juice Vinegar 0.1M NH4 OH FeSO4
White tile Pineapple Bleaching 0.25M HCN CH3 COONa
juice powder
Test tubes Amla juice Milk of 0.1M CH3 COOH CuSO4 5H2O
Magnesia
Universal Mango juice Sugar NH4 Cl
indicator
Milk Na2 SO3
Butter milk
Washing soda
, IV. Methodology (Schematic diagram)
Take a pH paper strip and place it pH level less than 7 Acidic
on a white tile.
Pour a drop of the sample on the
pH paper using a clean dropper.
pH level greater than 7 Basic
Observe the color of the pH paper.
Now compare the color obtained
on the pH paper with the different pH level equals to 7 Neutral
color shades of the standard color
pH chart and note down the pH
value.
Similarly, find the pH of the
remaining samples using a fresh
strip of pH paper and a separate
dropper for each sample.
Figure 1. Determination of pH using pH Paper
Take a small quantity of the given Now compare the color produced in the test tube with
sample in a test tube using a the different color shades of the standard color pH chart
dropper. and note down the pH value.
Acidic pH level less than 7
Using a dropper pour a few drops
of the universal indicator solution
into the test tube containing the Basic pH level greater than 7
sample.
Neutral pH level equals to 7
Shake the test tube well and note
the color developed in the test Similarly, find the pH of the
tube. remaining samples.
I. Objectives
- To determine the pH level of the given sample solutions
- To classify the samples as acidic, basic, or neutral based on the pH value.
- To understand how pH paper and universal indicator works.
II. Introduction
- The potential of Hydrogen or pH is a scale used to measure the acidity or basicity
of liquid solutions. This translates the values of the concentration of the hydrogen
ion. A solution with a pH less than 7 is considered acidic. A solution with a pH
greater than 7 is considered basic or alkaline. Solutions are considered neutral if
the pH level is 7. The pH of a solution is measured using pH indicators. The pH
indicators change color when in contact with acidic, basic, or neutral solutions.
III. Materials and Equipment
Materials Vegetable & House Hold Acids and Bases Salt in Water
fruit juices items in the Lab
pH color chart Lemon juice Common salt 0.1M HCl KCl
pH paper strip Tomato juice Baking soda 0.001M NaOH NaHCO3
Dropper Orange juice Vinegar 0.1M NH4 OH FeSO4
White tile Pineapple Bleaching 0.25M HCN CH3 COONa
juice powder
Test tubes Amla juice Milk of 0.1M CH3 COOH CuSO4 5H2O
Magnesia
Universal Mango juice Sugar NH4 Cl
indicator
Milk Na2 SO3
Butter milk
Washing soda
, IV. Methodology (Schematic diagram)
Take a pH paper strip and place it pH level less than 7 Acidic
on a white tile.
Pour a drop of the sample on the
pH paper using a clean dropper.
pH level greater than 7 Basic
Observe the color of the pH paper.
Now compare the color obtained
on the pH paper with the different pH level equals to 7 Neutral
color shades of the standard color
pH chart and note down the pH
value.
Similarly, find the pH of the
remaining samples using a fresh
strip of pH paper and a separate
dropper for each sample.
Figure 1. Determination of pH using pH Paper
Take a small quantity of the given Now compare the color produced in the test tube with
sample in a test tube using a the different color shades of the standard color pH chart
dropper. and note down the pH value.
Acidic pH level less than 7
Using a dropper pour a few drops
of the universal indicator solution
into the test tube containing the Basic pH level greater than 7
sample.
Neutral pH level equals to 7
Shake the test tube well and note
the color developed in the test Similarly, find the pH of the
tube. remaining samples.
