What must not be changed while balancing a chemical equation?
Answer and explanation
Correct answer: Subscripts in chemical formulae
Subscripts in chemical formulae must not be changed while balancing an equation, because changing a subscript changes the identity of the substance. For example, changing \(\mathrm{H_2O}\) to \(\mathrm{H_2O_2}\) changes water into hydrogen peroxide. An equation is balanced only by placing coefficients before formulae, so the number of molecules or moles and the quantitative ratio may change.
Frequently asked questions
What is the correct answer to this question?
Subscripts in chemical formulae
Why is this the correct answer?
Subscripts in chemical formulae must not be changed while balancing an equation, because changing a subscript changes the identity of the substance. For example, changing \(\mathrm{H_2O}\) to \(\mathrm{H_2O_2}\) changes water into hydrogen peroxide. An equation is balanced only by placing coefficients before formulae, so the number of molecules or moles and the quantitative ratio may change.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Chemical Reactions and Equations.
