In three test tubes A, B and C, three different liquids namely, distilled water, underground water and distilled water in which a pinch of calcium sulphate is dissolved, respectively are taken. An equal amount of soap solution is added to each test tube and the contents are shaken. In which test tube will the length of the foam (lather) be longest? Justify your answer.
The length of the foam (lather) will be the longest in test tube A, which contains only distilled water. This is because lather forms easily in soft water. Distilled water is soft water, hence lather will form easily in test tube A.
(Extra information: Tube B and C contain dissolved salts making them hard waters. They react with the soap solution and form scum because of the calcium and magnesium salts with little lather.)
Related Articles A student takes about 4 ml of distilled water in four test tubes marked P, Q, R and S. He then dissolves in each test tube an equal amount of one salt in one test tube, namely sodium sulphate in P, potassium sulphate in Q, calcium sulphate in R and magnesium sulphate in S. After that he adds an equal amount of soap solution in each test tube. On shaking each of these test tubes well, he observes a good amount of lather (foam) in the test tube marked.(A) P and Q (B) Q and R (C) P, Q and S (D) P, R and S
You have been provided with three test-tubes. One of these test -tubes contain distilled water and the other two contain an acidic and a basic solution respectively. If you are given only blue litmus paper, how will you identify the contents of each test-tube?
Take three test-tubes. Fill each of them with water. Label them A, B and C. Keep a snail in test-tube A, a water plant in test-tube B and in C, keep snail and plant both. Which test-tube would have the highest concentration of CO2?
Take three test tubes. Fill 3/4th of each with water. Label them A, B, and C. Keep a snail in test tube A, a water plant in test tube B, and in C, keep the snail and plant both. Which test tube would have the highest concentration of CO2?
Equal lengths of magnesium ribbons are taken in test tubes A and B. Hydrochloric acid (HCL) is added to test tube A, while acetic acid (CH3COOH) is added to test tube B. Amount and concentration taken for both the acids are same. In which test tube will the fizzing occur more vigorously and why?
You have been provided with three test tubes. one of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?
You are provided with three test tubes A, B and C as shown in figure with different liquids. What will you observe when you put(a) a piece of blue litmus paper in each test tube(b) a piece of red litmus paper in each test tube(c) a few drops of phenolphthalein solution to each test tube?
Blue litmus solution is added to two test tubes A and B containing dilute HC1 and NaOH solution respectively. In which test tube a colour change will be observed? State the colour change and give its reason.
You have been given three test tubes one of them contains distilled water and other contains the acidic and basic solution. If you have given only a red litmus paper how will you identify the content of each test tubes?
2 mL each of concentrated HCl, HNO3 and a mixture of concentrated HCl and concentrated HNO3 in the ratio of 3: 1 were taken in test tubes labelled as A, B and C. A small piece of metal was put in each test tube. No change occurred in test tubes A and B but the metal got dissolved in test tube C respectively. The metal could beAlAuCuPt
A student requires hard water for an experiment in his laboratory which is not available in the neighbouring area. In the laboratory, there are some salts, which when dissolved in distilled water can convert it into hard water. Select from the following groups of salts, a group, each salt of which when dissolved in distilled water will make it hard.(A) Sodium chloride, Potassium chloride(B) Sodium sulphate, Potassium sulphate(C) Sodium sulphate, Calcium sulphate(D) Calcium sulphate, Calcium chloride
A student adds 4 ml of acetic to a test tube containing 4 ml of distilled water. He then shakes the test tube and leaves it to settle. After about 10 minutes he observes:(a) A layer of water over the layer of acetic acid. (b) A layer of acetic acid over the layer of water.(c)A precipitate settling at the bottom of the test tube.(d) A clear colourless solution.
2 mL each of conc. HCl, cone. HNO3 and a mixture of conc. HCl and conc. HNO3 in the ratio of 3: 1 were taken in test tubes labelled as A, B, and C. A small piece of metal was put in each test tube. No change occurred in test tubes A But the metal got dissolved in test tube C. The metal could be.AlAu CuPt.
A student added few pieces of aluminium metal to two test tubes A and B containing aqueous solutions of iron sulphate and copper sulphate. In the second part of her experiment, she added iron metal to another test tubes C and D containing aqueous solutions of aluminium sulphate and copper sulphate.In which test tube or test tubes will she observe colour change? On the basis of this experiment, state which one is the most reactive metal and why.
Will the solution of sugar in distilled water conduct electricity?
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