Page 96 - Biology - XII

S. No. Experiment Observation Inference
(b) Heat it on the steam/water bath for 4–5 minutes
and cool it

3. For Sodium test:
In a clean and dry test-tube, take 2 ml of ash fi ltrate + Pale yellow precipitate is Sodium is
add little uranyl acetate + zinc acetate in acetic acid formed present.

Conclusion
The ash fi ltrate of tobacco leaves has diff erent types of mineral elements in it.

Precautions
1. Cut the big pieces of leaves into smaller pieces so that it is burnt easily. Collect the ash in a test tube
or a suitable glassware.
2. Use clean and dry test tubes.
3. Do not waste the fi ltrate and chemicals.

4. Note your observations in your record fi le.

VIVA VOCE

Q1. Give one precaution for this experiment.
Ans. The leaves should be burnt carefully to obtain the ash. One should keep away from the smoke/fumes
released. It may cause coughing.
Q2. Can’t you use cigarette/bidi ash for this experiment?
Ans. Cigarette tobacco ash/bidi tobacco ash can be used for study. (Note cigarette has a paper and bidi
has a leaf wrap or cover.)
Q3. Why did you use tobacco leaves for this experiment?
Ans. Because the amount of ash produced is in large quantity.

Q4. From where do these elements come in ash?
Ans. These elements are present in plant tissues. They are incombustible. Hence, appear/present in ash.
Q5. Which elements could you fi nd out in tobacco ash?
Ans. All the elements mentioned in the experiment. For example, sulphur, calcium, magnesium, sodium,
iron, chlorine, and phosphorus.

COMPETENCY BASED QUESTIONS

Multiple Choice Questions

Q1. Generally, metals absorbed by plants are

(a) solids (b) liquids (c) cations (d) anions

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