Question

while washing his hands at his aunts house, malik noticed that the soap didnt seem to lather as much as it did at his own house. he remembered hearing that \hard water\ has a higher mineral content than \soft water.\ he wondered if the soap lathered less at his aunts house due to the water having a higher mineral content. when he got home, malik filled 12 identical bottles with the same volume of distilled water. he added nothing to 4 of the bottles, one teaspoon of epsom salt to 4 of the bottles, and two teaspoons of epsom salt to the remaining 4 bottles. after adding a drop of soap to the first bottle, he put his thumb over the opening and shook it to make bubbles. he then used a ruler to measure the height of the bubbles. once he had repeated the procedure with all of the bottles, malik calculated the average height of the bubbles for each type of water. he found that the bottles containing only distilled water had the tallest column of bubbles, and the bottles with two teaspoons of epsom salt added had the shortest. he concluded that soap lathers less in hard water than it does in soft water. when malik told his aunt about the experiment, she confirmed that her house does have hard water.

Explanation:

Step1: Identify the experiment setup

Malik has 3 groups of bottles: pure distilled water (4 bottles), distilled water with 1 - teaspoon Epsom salt (4 bottles), distilled water with 2 - teaspoons Epsom salt (4 bottles).

Step2: Understand the measurement

He measures the height of bubbles after adding a drop of soap and shaking the bottle.

Step3: Analyze the results

The pure distilled - water bottles have the tallest bubbles, and the 2 - teaspoon Epsom salt bottles have the shortest. Since Epsom salt represents minerals in hard water, this shows that more minerals (harder water) lead to less lathering.

Answer:

Soap lathers less in hard water than in soft water.