Acids and bases - class-XI

Oxalic acid H2C2O4 is a diprotic acid. The first dissociation (H2C2O4 → HC2O4- + H+) is easier than the second (HC2O4- → C2O4²- + H+) because removing H+ from a negatively charged species (HC2O4-) is harder. K2 is typically 1/1000 of K1.

When metal carbonate is treated with dilute hydrochloric acid, the products formed are salt, water and carbon dioxide.

When a metal carbonate reacts with an acid, it produces a salt, water, and carbon dioxide gas. The general equation is: Metal Carbonate + Acid -> Salt + Water + Carbon Dioxide.

Acids liberate sulphur dioxide or hydrogen sulphide on reaction with metallic sulphides.

Marble chips are made up of by calcium carbonate. When they are treated with $HCl$, carbon dioxide gas is formed along with water and calcium chloride. ${ CaCO } _{ 3 }+HCl\rightarrow { CaCl } _{ 2 }+{ H } _{ 2 }O+{ CO } _{ 2 }$

Carbonates contain carboxylate ion which reacts with mineral acids to form carbon dioxide gas which gets evolved from the reaction mixture.

${CH _3}^-$ is an extremely strong base because it is the conjugate base of weak acid $CH _4$.

When $KHSO _4$ is added to concentrated $H _2SO _4$, the acidity remains constant.

Lewis base is a compound that should donate electrons easily.

NF3 is the least basic among the nitrogen trihalides because the highly electronegative fluorine atoms pull electron density away from the nitrogen atom, making the lone pair less available for donation.

More amount of acid reacts with equal amount of base, higher the amount of heat releases.

${H _2PO _4}^-$ is conjugate base of $H _3PO _4$  .