Q40
1 markMCQSection B

Raisins are wiped off gently before final weighing with help of:

Life Processes
Osmosis in Raisins (Practical)

Options

(1)a filter paper
(2)a cotton piece
(3)a cloth piece
(4)a polythene piece
Official Answer

a filter paper

filter paperblotting papersurface moistureadhering water

Marking Scheme

  • 11 Mark for selecting the correct option (A)

Hint

We need a highly absorbent material that removes surface water cleanly without leaving fibers or squeezing the delicate swollen raisins.

Quick Oral Answer

We use filter paper to gently blot dry the surface of the swollen raisins to ensure we only weigh the water absorbed inside the cells, preventing errors from external surface water.

Analysis & Explanation

Before weighing the swollen raisins, it is crucial to remove any liquid water adhering to their outer surface so that only the water absorbed inside the cells is measured.

  • Why 'a filter paper' is correct: Filter paper (or blotting paper) has high capillary action and absorbs surface moisture quickly and gently without applying squeezing pressure on the swollen raisins.
  • Why other options are incorrect:
  • A cotton piece or cloth piece can leave tiny lint or thread fibers on the sticky surface of the raisins, which would alter the final weight.
  • A polythene piece is non-porous and hydrophobic, meaning it cannot absorb or remove surface water at all.

Common Mistakes

  1. 1Squeezing the raisins while wiping, which forces the absorbed water out and leads to an underestimation of the absorption percentage.
  2. 2Using a cloth that leaves lint, which artificially increases the final weight.

Interesting Facts

Even a single drop of water left on the surface of a raisin can weigh around 0.05 g0.05\text{ g}, which can significantly skew the percentage calculation in micro-measurements.

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Frequently Asked Questions

How many marks does this question carry in CBSE Class 10 Science 2011?

This question carries 1 mark in the CBSE Class 10 Science 2011 examination.

Which chapter does this question come from in Science?

This question is from the chapter "Life Processes" in the CBSE Class 10 Science syllabus.

What topic does this question cover in Science?

This question covers the topic "Osmosis in Raisins (Practical)" from CBSE Class 10 Science.

What type of question is this in the CBSE Class 10 Science 2011 paper?

This is a MCQ question from Section B in the CBSE Class 10 Science 2011 paper.