SMPK 1 BPK PENABUR
BILINGUAL
B PK
PEN
WORKSHEET – ACID AND BASE
ABUR
Name:
___________________________________
Class/No:
___________________________________
Group:
___________________________________
AIM:
Identify the properties (acid or base) of sample that being tested
BASIC BUILDING CONCEPTS
Liquids all around us have
either acidic or basic (alkaline)
properties. For example, acids
taste sour; while, bases taste
bitter
and
feel
slippery.
However, both strong acids
and strong bases can be very
dangerous and burn your skin,
so it is important to be very
careful
when
using
such
chemicals. The strength of the
pH scale is determined by the
concentration of hydrogen ions
(H+)
where
concentration
a
of
high
H+
ions
indicate a low pH (acidic) and
a low concentration of H+ ions
indicate a high pH (base). The
pH scale ranges from 1 to 14
where 1 to 6 is classified as
acidic, 7 neutral (neither a
base or an acid) and 8 to 14 is
classified as basic. In this lab,
you
will
universal
use
litmus
indicator
to
and
test
common household liquids and determine the properties of tested sample. You will use natural
indicators to help you identify properties of sample through color change that produced by a pigment
called Flavin (an anthocyanin). Through this color change, you will be able to successfully identify the
approximate pH.
MATERIALS REQUIRED
Test tube, Rack, Syringe, Beaker glass, Litmus, Universal Indicator, Red Cabbage, Sample
PROCEDURE
Preparation
Using syringe, transfer 5 mL each sample into 2 test tubes (total 6 samples = 12 test tubes)
Observation using litmus:
1. Using forceps, dip the litmus into each sample then observe the change
2. Record the result on provided table
Observation using universal indicator:
1. Using forceps, dip the universal indicator into each sample then observe the change
2. Record the result on provided table
Observation using natural indicator (red cabbage):
1. Transfer 5 mL of natural indicator into each test tube (only 6 samples)
2. Observe the change and record the result on provided table
Observation using natural indicator (turmeric/other):
1. Transfer 5 mL of natural indicator into each test tube (only 6 samples)
2. Observe the change and record the result on provided table
OBSERVATION:
Sample
Initial Colour
Litmus
Universal
Natural Indicator
Other Natural
Indicator
(Red Cabbage)
Indicator
QUESTION
- List properties of Acid?
- List properties of Base?
- Which sample that categorized as acid and explain it!
- Which sample that categorized as base and explain it!
- Acid Rain is a phenomenon where rain becomes slightly acidic due to pollution in the air. Why do you
think acid rain is it a problem to oceans, rivers, lakes, ponds and the creatures that live in them? Give
a minimum of three examples.