1 TITLE: SOLUTION AND SOLUBILITY

2 AIM : To study the effect of different volumes of water on the rate of dissolving salt.3 HYPHOTHESIS : The larger the volume of water, the less the time taken to dissolve salt4 VARIABLES : a) Manipulated : Volume of water

b) Responding : Time taken to dissolve the salt c) Fixed/Constant : Mass of salt

5 APPARATUS/MATERIALS : Beam balance, stopwatch, 3 beakers (250 ml), fine salt, glass rod, measuring cylinder.

6 PROCEDURE : 1) Beaker A is filled with 50 ml of water, beaker B is filled with 100 ml of water and beaker C

is filled with 200 ml of water.2) Water is at room temperature.3) 10 g of salt is weighed with a beam balance and added to each beaker.4) The solution in each beaker is stirred at the same rate until all the salt dissolved completely. 5) Time taken for salt to dissolve is recorded for each beaker.

7 OBSERVATION :

Table of results: Mass of salt = 10 gram

1) From your observation, can salt grains still be seen after all salt is completely dissolved in water?

The salt grains cannot be seen anymore when all the salt is completely dissolved.

Beaker

Volume of water(ml)

Time taken to dissolve salt(second)

A 50 130B 100 60

150 PC 200 45

BEAKER A

Distilled water(50 cm3)

Finesalt

BEAKER B

Distilled water(100 cm3)Fine

salt

BEAKER C

Distilled water(200 cm3)Fine

salt

2) Which volume of water dissolves the salt:

(i) first : 200 ml of water in Beaker C dissolves salt first

(ii) last : 50 ml of water in Beaker A dissolves salt last.

Graph:

8 DISCUSSION AND ANALYSIS: 1. Which volume of water dissolves the salt :

(i) the fastest (ii) the slowest Give reason for each answer. (i) 200 ml of water in Beaker C dissolves salt the fastest because it has the largest volume of water (ii) 50 ml of water in Beaker A dissolves salt the slowest because it has the lowest volume of water.

2. Salt dissolves in water. What is the solute and solvent. Complete the word equation to represent the formation of salt solution.

0

20

40

60

80

100

120

140

0 50 100 150 200 250

Volume of water (ml)

Tim

e ra

ken

to d

isso

lve

salt

(s)

Graph time taken to dissolve salt against the volume of water

Salt dissolves in water to form salt solution. In word equation:

3. State the relationship between the volume of water and the time taken to dissolve salt in water.The larger the volume of water, the less time taken to dissolve salt

4. Based on Table 6.1, define operationally the “rate of dissolving salt” Rate of dissolving salt is the time taken to dissolve (10 g) salt completely in water

5. Based on table of results, what will happen to the time taken to dissolve salt when more than 200 ml of

water is used? If more than 200 ml of water is used, the time taken to dissolve salt will be less than 55 seconds

6. Based on the graph, predict the time taken to dissolve salt if 150 ml of water is used. ________seconds

9 CONCLUSION :

Time taken to dissolve salt is affected by the volume of water.

SOLVENTSOLUTE

SALT WATER SALT SOLUTION+