Advertisements
Advertisements
प्रश्न
Do basic solutions also have H+ (aq) ions? If yes, then why are these basic?
उत्तर १
Yes, basic solution also has H+ ions. However, their concentration is less as compared to the concentration of OH– ions that makes the solution basic.
उत्तर २
Yes, basic solutions also have H+ (aq) ions.
Generally, bases generate hydroxide ions when they are dissolved in water. Basic solutions also have H+ (aq) ions, which are obtained from the ionisation of water. The amount of H+ ions in basic solutions is very less compared with the amount of OH− ions. Hence, they are basic in nature.
APPEARS IN
संबंधित प्रश्न
Under what soil condition do you think a farmer would treat the soil of his fields with quick lime (calcium oxide) or slaked lime (calcium hydroxide) or chalk (calcium carbonate)?
What colour do the following indicators turn when added to a base or alkali (such as sodium hydroxide)?
litmus
What is an olfactory indicator?
What is the effect of adding sodium hydroxide solution to these olfactory indicators?
Why should curd and other sour foodstuffs (like lemon juice, etc.) not be kept in metal containers (such as copper and brass vessels)?
The indicators which turn red in acid solution are:
(a) turmeric and litmus
(b) phenolphthalein and methyl orange
(c) litmus and methyl orange
(d) phenolphthalein and litmus
What is the pH of a neutral solution?
What colour will universal indicator show if you add it to the following substances?
(a) potassium hydroxide, pH = 12
(b) soda water, pH = 5
(c) sulphuric acid, pH = 2
Two solutions X and Y have pH = 4 and pH = 8, respectively. Which solution will give alkaline reaction and which one acidic?
Fresh milk has a pH of 6. When it changes into curd (yogurt), will its pH value increase or decrease? Why?
What does the pH of a solution signify? Three solution A, B and C have pH values of 6, 4 and 10 respectively. Which of the solutions is highly acidic?
Someone put some universal indicator paper into vinegar. The pH is 3. What does this tell you about the vinegar?
A solution turns phenolphthalein indicator pink. The most likely pH of this solution will be:
(a) 6
(b) 4
(c) 9
(d) 7
Which of the following elements would from oxides which would indicate pH values less than seven, using moist pH paper?
Magnesium, Carbon, Sulphur, Hydrogen, Copper
The pH values of five solutions A, B, C, D and E are given below:
| A | 1 |
| B | 5 |
| C | 7 |
| D | 11 |
| E | 13 |
The pH values of five solutions A, B, C, D and E are given below:
| A | 1 |
| B | 5 |
| C | 7 |
| D | 11 |
| E | 13 |
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?
Turmeric and litmus are _________ acid-base indicators.
Take some lemon juice in a tumbler and add baking soda slowly. What do you see? What do you infer from this?
Using the knowledge of acids and bases, write a secret message with the help of baking soda and beet root. Explain how it works.
(Hint: Prepare baking soda solution in water. Use this solution to write the message on a sheet of white paper with a cotton bud. Rub a slice of fresh beetroot over the message.)
