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प्रश्न
In order to study saponification reaction, we first prepare 20% solution of sodium hydroxide. If we record the temperature of this solution just after adding sodium hydroxide flakes to water and also test its nature using litmus, it may be concluded that the process of making this solution is
(A) exothermic and the solution is alkaline
(B) endothermic and the solution is alkaline
(C) endothermic and the solution is acidic
(D) exothermic and the solution is acidic
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उत्तर
Dissolution of sodium hydroxide in water evolves large amount of heat. Thus, it is an exothermic reaction. Since sodium hydroxide is a base, its solution in water will be alkaline when tested with litmus paper (red litmus turns blue).
Hence, the correct option is A.
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संबंधित प्रश्न
A student adds 2 mL of acetic acid to a test tube containing 2 mL of distilled water. He then shakes the test tube well and leaves it to settle for some time. After about 5 minutes he observes that in the test tube there is :
(A) a clear transparent colourless solution
(B) a clear transparent pink solution
(C) a precipitate settling at the bottom of the test tube
(D) a layer of water the layer of acetic acid
Complete the following chemical equations :CH3COOH+NaOH→
When you add a few drops of acetic acid to a test-tube containing sodium bicarbonate powder, which one of the following is your observation?
(A) No reaction takes place
(B) A colourless gas with pungent smell is released with brisk effervescence
(C) A brown coloured gas is released with brisk effervescence
(D) Formation of bubbles of a colourless and odourless gas
What is the common name of methanoic acid.
What is the common name of methanol?
Complete the following equation:
`CH_3 COOH + CH_2 H_5 OH` 
Identify the term or substance based on the descriptions given below:
Hydrocarbon containing a triple bond used for welding purposes
A compound X when treated with an organic acid Y (having vinegar-like smell) in the presence of the acid Z, forms a compound P which has a fruity smell.
- Identify X, Y and Z
- Write the structural formula of X and Y.
- What type of compound is P?
- Name the above reaction.
- If compounds X and Y both have 2 carbon atoms. Write the reaction.
Ketone : –CO– : : Ester : _______
Give the balanced chemical equation of the following reaction:
Neutralization of NaOH with ethanoic acid.
