Advertisements
Advertisements
प्रश्न
Answer the following question:
What is the universal indicator? Does Mg (OH)2 react with sodium hydroxide? If not, why?
Advertisements
उत्तर
- Universal indicator is an indicator which is a mixture of several indicators.
- It has a very wide range and can indicate pH value almost from 0 to 14.
- When one or two drops of the universal indicator are added to a solution, it changes its colour. This colour is matched against the colour on a standard colour chart (usually given on its bottle) to find the pH, and the pH value can be read. This indicates the strength of the solution too.
- Universal indicator is available as a solution or in the form of paper strips.
- Mg(OH)2 does not react with sodium hydroxide as both are bases.
APPEARS IN
संबंधित प्रश्न
Dilute NaOH can be tested with
(a) red litmus paper
(b) blue litmus paper
(c) lime water
(d) Na2CO3
| Column A | Column B | ||
| i | eosin | 1 | losing hydrogen |
| ii | oxidation | 2 | synthetic indicator |
| 3 | losing oxygen | ||
| 4 | natural indicator |
Complete and balance the following chemical equations:
CuO (s) + HCI (aq) →
Fill in the blank in the following sentences:
Substances do not show their acidic properties without.......................... .
What happens when an acid reacts with a metal hydrogencarbonate? Write equation of the reaction which takes place.
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 substance X which is used as an antacid reacts with dilute hydrochloric acid to produce a gas Y which is used in one type of fire-extinguisher. Name the substance X and gas Y. Write a balanced equation for the chemical reaction which takes place.
Name the gas evolved when zinc granules are treated/heated with:
hydrochloric acid solution
What ions are present in the solutions of following substances? (write the symbols only)
Sulphuric acid
Is PbO2 a base or not? Comment.
What are esters? How are esters prepared? Write the chemical equation for the reaction involved. What happens when an ester reacts with sodium hydroxide? Write the chemical equation for the reaction and also state the name and use of this reaction.
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 _______
What is a neutralization reaction? Give an example.
A sample of soil is mixed with water and allowed to settle. The clear supernatant solution turns the pH paper yellowish-orange. Which of the following would change the colour of this pH paper to greenish-blue?
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
On placing a copper coin in a test tube containing green ferrous sulphate solution, it will be observed that the ferrous sulphate solution ______.
Two salts 'X' and 'Y' are dissolved in water separately. When phenolphthalein is added to these two solutions, the solution 'X' turns pink and the solution 'Y' does not show any change in colour, therefore 'X' and 'Y' are:
Consider the following salt:
NH4X
If in salt NH4X, X is nitrate, then its solution will give what colour with a universal indicator? Why?
