Why does dry $HCl$ gas not change the colour of the dry litmus paper ?
Colour of the litmus paper is changed by the hydrogen ions. Dry $HCl$ gas does not contain $H ^{+}$ ions. It is only in the aqueous solution that an acid dissociates to give ions.
since in this case, neither $HCl$ is in the aqueous form nor the litmus paper is wet, therefore, the colour of the litmus paper does not change.
Write word equations and then balanced equations for the reaction taking place when -
$(a)$ dilute sulphuric acid reacts with aluminium powder.
$(b)$ dilute hydrochloric acid reacts with iron filings.
You have been provided with three test tubes. One of them contains distilled water and the other two contaln an acidic solution and a basic solution, respectlvely. If you are glven only red litmus paper. how will you identify the contents of each test tube ?
Compounds such as alcohols and glucose also contain hydrogen but are not categorised as acids. Describe an Activity to prove it.
Why do acids not show acidic behaviour in the absence of water ?
What is the common name of the compound $CaOCl_2$ ?