MILK OF MAGNESIA AND STOMACH ACID EXPERIMENT
PROCEDURE OF THE EXPERIMENT
1. Use 50.0𝑐𝑚3 measuring cylinder to measure 50 ml of stomach acid each into three
conical flask labelled A, B and C
2. Measure 30 ml of milk of magnesia into a beaker M1
3. Measure 30 ml of milk of magnesia into a beaker. M2
4. Measure 30 ml of milk of magnesia into a beaker. M3
5. Add two or three drops of indicator each into the conical flasks labelled M1, M2 and M3.
6. Use a dropper to add stomach acid into the conical flask labelled M1 from the flask
labeled A.
7. Measure the volume of milk of stomach acid used.
8. Stop adding when the colour has changed from yellow to pink
9. Use a dropper to add stomach acid into the conical flask labelled M2 from the beaker
labeled B
10. Stop adding when the colour has changed from orange to pink
11.
12. Use a dropper to add stomach acid into the conical flask labelled M3 from the beaker
labeled C
13. Stop adding when the colour has changed from orangeto pink
14. Record all answers in 1 decimal place.
RESULT OF THE EXPERIMENT
Exp. Amount of
Stomach
acid used/g
1
2
3
23.0
32.0
40.0
Volume of
Volume of
milk of
stomach acid
magnesia
measured/ cm3
3
measured/cm
30.0
30.0
30.0
Volume of
stomach acid
left /cm3
Volume of
stomach
acid used
/cm3
[3]
ANSWER THE FOLLOWING QUESTIONS
1. Which solution was kept constant throughout the experiment? Tick the correct box
Milk of magnesia
Stomach acid
Amount of Stomach acid
[1]
2. Why was this solution kept constant? Tick any two correct boxes.
I.
It was kept constant to make sure the effect of the controlled variable can be
observed.
II.
It was kept constant in order that the effect of the independent variable can be
observed in the experiment
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III.
It was kept constant so that we can obtain a fair result in the measured variable.
[2]
3. Which varible is the independent variable in the experiment?. Tick the correct box
below. Volume of the stomach acid
Volume of the milk of magnesia
Amount of stomach acid used
[1]
4. Explain the choice of your answer in question 3 above.
……………………………………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………………………..
[1]
5. Identify the dependent variable in the experiment. Tick the correct box.
. Volume of the stomach acid
Volume of the milk of magnesia used
Amount of stomach acid used
[1]
6. Give reason for your answer in question 5 above. Tick any two correct boxes.
I.
It was the measured variable
II. It was the variable that was intentionally
changed so that we can see its effect in the experiment
III. It was the
varible that kept on changing as the experiment progresses.
[2]
7. Some apparatus were used during the experiment. One of them is a dropper.
Mention two other apparatus used in the experiment
………………………………………………………… and ……………………………………………
[2]
8. What was the colour of the indicator in the stomach acid at the beginning and at the
end of the experiment?
Colour at the start………………………………. Colour at the end …………………………
[2]
9. What is the name of the salt formed in the experiment?
Name of salt formed………………………………………………………………………………………….
[1]
10. Mention one precaution taken in during the experiment
Precaution…………………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………………..
[1]
What is the general name of this experiment you have carried out? Tick the correct box
Salt making
Neutralization
Precipitation
[1]
11. Mention two units used in this experiment
……………………………………………. and ……………………………………………………………..
[2]
[TOTAL: 20]
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