Question map
Not attempted Correct Incorrect ★ Bookmarked
Loading…
Q97 (CAPF/2021) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Quantitative aptitude topics Answer Verified

How much water is to be added to 75 ml of alcohol so that the mixture contains 25% of alcohol?

Result
Your answer: —  Â·  Correct: B
Explanation

To find the amount of water needed, we use the principle of dilution where the volume of the solute (alcohol) remains constant. The initial volume of pure alcohol is 75 ml. We want this 75 ml to represent 25% of the final mixture's total volume. Let the total volume of the final mixture be 'V'. According to the percentage formula, 25% of V = 75 ml, which simplifies to 0.25 * V = 75. Solving for V gives V = 75 / 0.25 = 300 ml. The total volume of the mixture is the sum of the alcohol and the added water. Therefore, the volume of water to be added is the total volume minus the initial alcohol volume: 300 ml - 75 ml = 225 ml [1]. This calculation ensures the alcohol concentration is reduced to the target 25% by increasing the solvent volume.

Sources

  1. [1] https://www.mathcentre.ac.uk/resources/uploaded/diluting-a-solution.pdf
How others answered
Each bar shows the % of students who chose that option. Green bar = correct answer, blue outline = your choice.
Community Performance
Out of everyone who attempted this question.
55%
got it right
✓ Thank you! We'll review this.

SIMILAR QUESTIONS

CDS-II · 2013 · Q30 Relevance score: -3.76

A liquid initially contracts when cooled down to 4°C but on further cooling down to 0°C, it expands. The liquid is :

NDA-I · 2011 · Q33 Relevance score: -4.00

A student by chance mixed acetone with alcohol. This mixture of acetone and alcohol can be separated by:

CDS-I · 2011 · Q85 Relevance score: -4.24

Which one among the following would expand the most on being heated?

NDA-II · 2009 · Q86 Relevance score: -4.42

Equal quantities (50 ml) of the following four samples of water are placed in four beakers of 100 ml capacity. Their boiling points are determined accurately using the same thermometer. Which sample of water will have the lowermost boiling point as compared to other three samples?