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प्रश्न
What effect does the concentration of OH− ions have on the nature of a solution?
उत्तर
Bases furnish hydroxide ions (OH- ions) when dissolved in water. The concentration of hydroxide ions increases as bases dissolve in water. With the increase in the concentration on OH- ions, the pH also increases, thus, strengthening the basic nature of the solution.
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संबंधित प्रश्न
Five solutions, A, B, C, D and E, when tested with universal indicator, showed pH as 4, 1, 11, 7 and 9, respectively. Which solution is
- neutral?
- strongly alkaline?
- strongly acidic?
- weakly acidic?
- weakly alkaline?
Arrange the pH in increasing order of hydrogen-ion concentration.
Sodium hydroxide turns blue litmus red.
Fill in the blank in the following sentences:
Acids have a ..........................taste and they turn..........................litmus to..........................
The property which is not shown by acids is:
(a) they have sour taste
(b) they feel soapy
(c) they turn litmus red
(d) their pH is less than seven
If someone is suffering from the problem of acidity after overeating, which of the following would you suggest as remedy?
Lemon juice, Vinegar, Banking soda solution
Give reason for your choice.
A sample of rain water turned universal indicator paper yellow. What would you expect it pH to be? Is it a strong or a weak acid?
Here are some results of solutions tested with universal indicator paper:
| Sulphuric acid | : Red |
| Metal polish | : Dark blue |
| Washing-up liquid | : Yellow |
| Milk of magnesia | : Light blue |
| Oven cleaner | : Purple |
| Car batter acid | : Pink |
Arrange the solutions in order of their increasing pH value (starting with the one with the lowest pH).
A group of students measured the pH of some substances they found in their homes. Their results are given in the following table:
| Substance | pH | Substance | pH |
| Apples | 3.0 | Salt | 7.0 |
| Baking soda | 8.5 | Sugar | 7.0 |
| Black coffee | 5.0 | Toothpaste | 9.0 |
| Household ammonia | 12.0 | Vinegar | 3.0 |
| Lemon juice | 2.5 | Washing soda | 11.5 |
| Milk | 6.5 |
(a) What would the students have used to measure the pH?
(b) Which solution is the most acidic?
(c) Which solution is the most alkaline?
(d) Which solutions are neutral?
(e) Which solution can be used to treat wasp stings?
(f) Which solutions can be used to treat bee stings?
How will you prepare a china rose indicator?
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