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प्रश्न
Dilute NaOH can be tested with
(a) red litmus paper
(b) blue litmus paper
(c) lime water
(d) Na2CO3
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उत्तर
(a) red litmus paper
Sodium hydroxide when dissolved in water undergoes the following
reaction:
NaOH(s) + aqs → Na+(aq) + OH−(aq)
The dissociated OH− ions turn moist red litmus paper blue.
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संबंधित प्रश्न
From which plant is litmus paper or litmus solution obtained?
- Moss
- Rose
- Hibiscus
- Lichen
Metal compound A reacts with dilute hydrochloric acid to produce effervescence. The gas evolved extinguishes a burning candle. Write a balanced chemical equation for the reaction if one of the compounds formed is calcium chloride.
What happens when an acid reacts with a base? Explain by taking the example of hydrochloric acid and sodium hydroxide. Give equation of the chemical reaction which takes place. What is the special name of such a reaction?
What happens when an acid reacts with a metal oxide? Explain with the help of an example. Write a balanced equation for the reaction involved.
A solution reacts with marble chips to produce a gas which turns lime water milky. The solution contains ______.
What ions are present in the solution of the following substance? (write the symbols only)
Sodium hydroxide
Define an acid.
State the common and chemical names of the compound formed when plaster of Paris is mixed with water.
State two uses of the following compound:
Hydrochloric acid
Read the following statements:
I. When a red litmus paper is dipped into reaction mixture of a saponification reaction, it turns blue and the reaction is exothermic.
II. When a blue litmus paper is dipped into reaction mixture of a saponification reaction, its colour does not change and the reaction is exothermic.
III. When a red litmus paper is dipped into reaction mixture of a saponification reaction, its colour does not change and the reaction is endothermic.
IV. When a blue litmus paper is dipped into reaction mixture of a saponification reaction, its colour does not change and the reaction is endothermic.
Which of the above statements are correct:
(A) I, and II
(B) II and III
(C) III and IV
(D) I and IV
Choose the correct alternative and rewrite the following sentence.
Phenolphthalein is ___________ type of indicator.
Answer the following question:
What is the universal indicator? Does Mg (OH)2 react with sodium hydroxide? If not, why?
With the help of suitable examples explain the term neutralization and the formation of –
- acidic,
- basic and
- neutral salts
Magnesium hydroxides are used for treating _______
Calcium phosphate is present in tooth enamel. Its nature is
Which of the following gives the correct increasing order of acidic strength?
Which of the following statements is true for acids?
Which of the following are present in a dilute aqueous solution of hydrochloric acid?
Consider the following salt:
YCl
What would be the pH of the solution if, in YCl, Y is sodium? Give a reason for your answer.
Consider the following salt:
\[\ce{ZCO3}\]
What would be the change in colour in blue litmus if \[\ce{ZCO3}\] is added to it and Z is potassium?
