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प्रश्न
The label on the bottle of chemical is spoiled. How will you find whether the chemical is acidic or not?
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उत्तर
The chemical is acidic or not checked in two ways:
- By use of litmus paper:
- If the given solution is acidic, it turns blue litmus to red litmus.
- If the given solution is basic, it turns red litmus to blue litmus.
- If the given solution is neutral, there is no effect on litmus paper.
- By use of indicators:
- If the given solution is acidic, it turns methyl orange to red.
- If the given solution is basic, it turns methyl orange to yellow.
- If the given solution is neutral, there is no effect on methyl orange indicator.
संबंधित प्रश्न
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?
Give the names and formulae of two strong acids and two weak acids.
Name one animal and one plant whose stings contain formic acid (or methanoic acid).
What colour does phenolphthalein indicator turn when added to an alkali (such as sodium hydroxide)?
A white shirt has a yellow stain of curry. When soap is rubbed on this shirt during washing, the yellow stain turns reddish-brown. On rinsing the shirt with plenty of water, the reddish-brown stain turns yellow again.
Name the natural indicator present in curry stain.
State one observation for each of the following :
A small piece of zinc is added to dilute hydrochloric acid
Give the name and formula of two : Non-volatile acids
Choose the correct answer from the options given below
Which of them occurs in solid state?
Fill in the missing data in the following table
| Name of the salt | Formula | Salt obtained from | ||
| Base | Acid | |||
| (i) | Ammonium chloride | NH4Cl | NH4OH | ______ |
| (ii) | Copper sulphate | ______ | ______ | H2SO4 |
| (iii) | Sodium chloride | NaCl | NaOH | ______ |
| (iv) | Magnesium nitrate | Mg(NO3)2 | ______ | HNO3 |
| (v) | Potassium sulphate | K2SO4 | ______ | ______ |
| (vi) |
Calcium nitrate | Ca(NO3)2 | Ca(OH)2 | ______ |
Complete the following equation.
ZnO + 2HCl → ______ + ______.
