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प्रश्न
From which plant is litmus paper or litmus solution obtained?
- Moss
- Rose
- Hibiscus
- Lichen
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उत्तर
(d) Lichen.
Litmus is a water soluble mixture of different dyes extracted from lichens, especially Roccella tinctoria.
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संबंधित प्रश्न
| Column A | Column B | ||
| i | eosin | 1 | losing hydrogen |
| ii | oxidation | 2 | synthetic indicator |
| 3 | losing oxygen | ||
| 4 | natural indicator |
How is the concentration of hydronium ions (H3O+) affected when a solution of an acid is diluted?
Complete and balance the following chemical equations:
CuO (s) + HCI (aq) →
A solution reacts with zinc granules to give a gas which burns with a 'pop' sound. The solution contains:
(a) Mg(OH)2
(b) Na2CO3
(c) NaCl
(d) HCl
Hydrochloric acid reacts with a metal X to form a gas Y which burns with a 'pop' sound. Sodium hydroxide solution also reacts with the same metal X (on heating) to form the same gas Y.
Name X and Y
Hydrochloric acid reacts with a metal X to form a gas Y which burns with a 'pop' sound. Sodium hydroxide solution also reacts with the same metal X (on heating) to form the same gas Y.
Write the chemical equation of the reaction of metal X with (i) hydrochloric acid, and (ii) sodium hydroxide solution.
Complete and balance the following chemical equations:
`Ca(OH)_2 + Cl_2 ->`
Explain why, sodium hydrogencarbonate is used as an antacid.
Write the chemical formula of washing soda. How can it be obtained from baking soda? List two industries in which washing soda is used for other purposes than washing clothes.
Magnesium hydroxides are used for treating _______
The table given below shows the reaction of a few elements with acids and bases to evolve Hydrogen gas.
| Element | Acid | Base |
| A |
✗
|
✗ |
| B |
✓
|
✓ |
| C | ✓ | ✗ |
| D | ✓ | ✓ |
Which of these elements form amphoteric oxides?
A student added 10 g of calcium carbonate in a rigid container, secured it tightly and started to heat it. After some time, an increase in pressure was observed, the pressure reading was then noted at intervals of 5 mins and plotted against time, in a graph as shown below. During which time interval did maximum decomposition take place?
If a few drops of a concentrated acid accidentally spills over the hand of a student, what should be done?
Common salt besides being used in kitchen can also be used as the raw material for making
- washing soda
- bleaching powder
- baking soda
- slaked lime
Vinegar is ______ in taste.
Are all acids corrosive in nature? Name a few acids which are non-corrosive and may be part of our food.
Copper or brass cooking vessels are coated with tin metal. Why?
“All acids contain one or more hydrogen atoms, but not all substances containing hydrogen are acids.” Support this statement with examples.
Consider the following salt:
NH4X
If in salt NH4X, X is nitrate, then its solution will give what colour with a universal indicator? Why?
Some metals react with acids to produce salt and hydrogen gas. Illustrate it with an example. How will you test the presence of this gas?
