$Mg+H_{2}S{O}_4\to \underset{–}{A}+H_2\left(Mg\right)\left(dilute\right)$

$Mg+2H_{2}S{O}_4\to \underset{–}{A}+\underset{–}{B}+2H_{2}O.\left(Concentrated\right)$ A & B are

Q. What type of reactions are represented by the following equations?
(a) $\mathrm{CaO}+{\mathrm{CO}}_2\underset{}{\to }{\mathrm{CaCO}}_3$
(b) $2\mathrm{Na}+2{\mathrm{H}}_2\mathrm{O}\underset{}{\to }2\mathrm{NaOH}+{\mathrm{H}}_2$
(c) $\mathrm{Mg}+{\mathrm{CuSO}}_4\underset{}{\to }{\mathrm{MgSO}}_4+\mathrm{Cu}$
(d) ${\mathrm{NH}}_4{\mathrm{NO}}_2\underset{}{\to }{\mathrm{N}}_2+2{\mathrm{H}}_2\mathrm{O}$
(e) ${\mathrm{CuSO}}_4+2\mathrm{NaOH}\underset{}{\to }\mathrm{Cu}(\mathrm{OH}{)}_2{\mathrm{Na}}_2{\mathrm{SO}}_4$

Q.

$Mg+H_{2}S{O}_4\to \underset{–}{A}+H_2\left(Mg\right)\left(dilute\right)$

$Mg+2H_{2}S{O}_4\to \underset{–}{A}+\underset{–}{B}+2H_{2}O.\left(Concentrated\right)$ A & B are

Q. Which among the following is a displacement reaction?
(a) H₂SO₄ + Mg ⟶ H₂ + MgSO₄
(b) CaCO₃ ⟶ CaO + CO₂
(c) 2H₂ + O₂ ⟶ 2H₂O
(d) CuSO₄.5H₂O ⟶ CuSO₄ + 5H₂O

Q.

When magnesium metal reacts with sulphuric acid it forms magnesium sulphate along with the evolution of hydrogen gas.

$Mg+H_{2}S{O}_4$$\to$$MgS{O}_4$+$H_2$

For experimental studies the conditions of the reaction was modified and rate of reaction was monitored. In which of the following case the occurance of the reaction is fastest?

Q. Why can't Cu+H2SO4form like Cuso4+h2
​like Mg+H2So4 forms MgSo4