Balance the following chemical equ | 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?

Why does micelle formation take place when soap is added to water? Will a micelle be formed in other solvents such as ethanol also?

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.

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

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

Name two metals which are found in nature in the free state.

Suggest some approaches towards the conservation of forests.

Why does bread mould grow profusely on a moist slice of bread rather than on a dry slice of bread?

What is the advantage of having four chambered heart?

How is the small intestine designed to absorb digested food?

Write the balanced equation for the following chemical reactions.

1. Hydrogen  +  Chlorine  →  Hydrogen chloride
2. Barium chloride  +  Aluminium sulphate  →  Barium sulphate  +  Aluminium chloride
3. Sodium  +  Water  →  Sodium hydroxide  +  Hydrogen