Acids, Bases and Salts — Science STD 10 — Question

Why are decomposition reactions called the opposite of combination reactions ? Explain with equations of these reactions.

InMendele′ ev’s Periodic Table the elements were arranged in the increasing order of their atomic masses. However, cobalt with atomic mass of 58.93amu was placed before nickel having an atomic mass of 58.71amu. Give reason for the same.

What type of oxides are formed when non-metals react with oxygen? Explain with an example.

Write the balanced chemical equations for the following reaction.
Sodium hydrogencarbonate on reaction with hydrochloric acid gives sodium chloride, water and liberates carbon dioxide.

State two characteristics of a homologous series.

A milkman adds a very small amount of baking soda to fresh milk.

1. Why does he shift the pH of the fresh milk from 6 to slightly alkaline?
2. Why does this milk take a long time to set as curd?

Give the name and structural formula of one member each of the following:

1. Alkane.
2. Alkene.
3. Alkyne.
4. Cycloalkane.

What is a redox reaction? Explain with an example.

Name the functional groups present in the following compounds:

1. CH₃CHO
   
2. CH₃CH₂COOH
   
3. CH₃COCH₃
   
4. CH₃CH₂CH₂OH
   

Give the molecular formula of one homologue of each of the following:

1. C₃H₆
2. C₂H₆
3. C₂H₂