Which gas is usually liberated when an a | Class 10 Science Chapter Acids, Bases and Salts, Acids, Bases and Salts NCERT Solutions

When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.

Outline a project which aims to find the dominant coat colour in dogs.

Draw the structure for the following compounds.                

       (i)    Ethanoic acid             (ii)   Bromopentane*
       (iii)  Butanone                   (iv)   Hexanal.

*Are structural isomers possible for bromopentane?

A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistance, which may be used separately, in series, or in parallel. What are the currents in the three cases?

How is the sex of the child determined in human beings?

(a)  What property do all elements in the same column of the Periodic Table as boron have in common?
(b)  What property do all elements in the same column of the Periodic Table as fluorine have in common?

Calculate the number of electrons constituting one coulomb of charge.

A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?

What is an homologous series? Explain with an example.

Why is variation beneficial to the species but not necessarily for the individual?

Explain why the planets do not twinkle.

Differentiate between inherited and acquired characters. Give one example for each type.

Suggest suitable mechanism (s) for waste management in fertiliser industries.

How is the process of pollination different from fertilisation?

Why is the flow of signals in a synapse from axonal end of one neuron to dendritic end of another neuron but not the reverse?

What changes can you make in your habits to become more environment-friendly?

What will happen if mucus is not secreted by the gastric glands?

Besides gallium, which other elements have since been discovered that were left by Mendeléev in his Periodic Table? (any two)

A student has difficulty reading the blackboard while sitting in the last row. What could be the defect the child is suffering from? How can it be corrected?

Explain the importance of soil for plant growth.