The City School
Academic Year 2020-21
Class 7
Subject: Science
Topic: Mixtures
Worksheet # 06-c
Student’s Name:
Date:
Lesson Objective: To describe mixtures as two or more elements and or compounds that are not
chemically combined, to recognise that elements and compounds melt and boil at particular
temperatures but mixtures do not
Kindly refer to the textbook (ILSS Book 2); pg-78 & 79 for solving the questions below:
Q1:
Activity I: Use a thermometer (you may use a digital thermometer if available) to record the
temperature of pure ice placed in a beaker when melting, and carry out the same process to
measure the temperature of frozen salt water and record its melting point.
You are required to enter your observations in the table below:
Melting Point (0 C) of Pure Ice
Melting Point (0 C) of Frozen Salt Water
Q2:
Activity II: Heat pure water in a beaker and record the temperature at which it boils. Then
carry out the same activity simultaneously with some salt added to the water and measure
the boiling point of salt water.
You are required to enter your observations in the table below:
Boiling Point (0 C) of Pure Water
Boiling Point (0 C) of Salt Water
Q3: Compare your observations of both Activity I & II and deduce a conclusion for your
results.
Q4: From the picture given below, identify which of the substances shown in the boxes
belong to compound, mixture or element category.
Box
A
B
C
D
E
F
G
H
I
Compound, Mixture or Element
Compound
Mixture
Mixture
Mixture
Element
Element
Mixture
Element
Compound
Q.5: DO elements ,compounds and mixtures have fixed melting and boiling points?
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