1. All bases dissolve in water.
2. Bases which are soluble in water are called alkalis.
3. An alkali is soapy to touch, bitter and corrosive.
4. Addition of water to an alkali generates heat.
Which of the statements given above are correct ?
Analyzing Statements on Bases and Alkalis
This question requires evaluating the correctness of four statements concerning bases and alkalis. Let's examine each statement:
Statement 1: All bases dissolve in water.
This statement is incorrect. While all alkalis are bases, not all bases are alkalis. Bases are compounds that can accept protons or donate electron pairs. Only those bases that dissolve in water are defined as alkalis.
Statement 2: Bases which are soluble in water are called alkalis.
This statement is correct. This is the precise definition of an alkali in chemistry. Alkalis are a subset of bases that exhibit solubility in water.
Statement 3: An alkali is soapy to touch, bitter and corrosive.
This statement is correct. These are indeed characteristic properties of alkalis. They often feel slippery or soapy due to saponification of skin oils, taste bitter (though tasting chemicals is strongly discouraged), and can cause damage to materials and living tissues (corrosive).
Statement 4: Addition of water to an alkali generates heat.
This statement is correct. The process of dissolving an alkali (or an acid) in water is typically exothermic. This means that the dissolution process releases energy in the form of heat, causing the temperature of the solution to rise.
Summary of Correct Statements
Based on the analysis:
- Statement 1 is incorrect.
- Statement 2 is correct.
- Statement 3 is correct.
- Statement 4 is correct.
Therefore, the statements that are correct are 2, 3, and 4.
Similar Questions
Number of electrons present in the species H2, He, H2 and O2 respectively are:
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- Which of the following foods would you advise to neutralise excess stomach acids?
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