A shiny brown coloured element $‘X’$ on heating in air becomes black in colour. Name the element $‘X’$ and the black coloured compound formed.
$‘X’$ is copper $(Cu)$ and the black-coloured compound formed is copper oxide $(CuO)$. The equation of the reaction involved on heating copper is given below.
$\mathop {2Cu\,}\limits_{(Shiny\,brown\,in\,\,colour)} + \,{O_2}\,\xrightarrow{{Heat}}\mathop {2CuO}\limits_{(Black\,in\,\,colour)} $
What happens when dilute hydrochloric acid is added to iron fillings ? Tick the correct answer.
Why is respiration considered an exothermic reaction ? Explain.
$Fe _{2} O _{3}+2 Al \rightarrow Al _{2} O _{3}+2 Fe$
The above reaction is an example of a
Give an example of a double displacement reaction other than the one given in image.
Why are decomposition reactions called the opposite of combination reactions? Write equations for these reactions.