When Calcium oxide is added to water taken in a beaker, rise in temperature is observed. However, when Barium hydroxide is mixed with Ammonium chloride, a fall in temperature is observed. Why?
.A Magnesium ribbon is burnt in oxygen to give a white compound X accompanied by emission of light. If the burning ribbon is now placed in an atmosphere of nitrogen, it continues to burn and forms a compound Y.
(i).Write the chemical formulae of X and Y
(ii).Write the balanced chemical equation when X is dissolved in water
When Calcium oxide is added to water taken in a beaker, rise in temperature is observed. However, when Barium hydroxide is mixed with Ammonium chloride, a fall in temperature is observed. Why?
.A Magnesium ribbon is burnt in oxygen to give a white compound X accompanied by emission of light. If the burning ribbon is now placed in an atmosphere of nitrogen, it continues to burn and forms a compound Y.
(i).Write the chemical formulae of X and Y
(ii).Write the balanced chemical equation when X is dissolved in water
1) When Calcium oxide is added to water taken in a beaker, following reaction takes place:
CaO + H2O → Ca(OH)2 + heat
Since the reaction is exothermic, rise in temperature is observed.
When Barium hydroxide is mixed with Ammonium chloride, following reaction takes place:
2NH4Cl + Ba(OH)2 → BaCl2 + 2NH3 + 2H2O
This is an endothermic reaction.Thus, a fall in temperature is observed.
2. (i) X is MgO and Y is Mg3N2
(ii) MgO + H2O → Mg(OH) 2
1) When Calcium oxide is added to water taken in a beaker, following reaction takes place:
CaO + H2O → Ca(OH)2 + heat
Since the reaction is exothermic, rise in temperature is observed.
When Barium hydroxide is mixed with Ammonium chloride, following reaction takes place:
2NH4Cl + Ba(OH)2 → BaCl2 + 2NH3 + 2H2O
This is an endothermic reaction.Thus, a fall in temperature is observed.
2. (i) X is MgO and Y is Mg3N2
(ii) MgO + H2O → Mg(OH) 2
