Write a balanced chemical equation with | Class 10 Science Chapter Chemical reaction and Equation, Chemical reaction and Equation 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?

Where do plants get each of the raw materials required for photosynthesis?

When do we consider a person to be myopic or hypermetropic?
Explain using diagrams how the defects associated with myopic and hypermetropic eye can be corrected?

Give any two ways in which non-biodegradable substances would affect the environment.

What would be the ratio of chromosome number between an egg and its zygote? How is the sperm genetically different from the egg?

Draw the structure for the following compounds.                

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

*Are structural isomers possible for bromopentane?

Can the wing of a butterfly and the wing of a bat be considered homologous organs? Why or why not?

Describe the process of urine formation in kidneys.

Which signals will get disrupted in case of a spinal cord injury?

Give reasons why acquired characters are not inherited.

Suggest a few useful ways of utilising waste water.