question_answer

Identify X, Y, Z and K.

X	Y	Z	K
(a) \[{{H}_{2}}O\]	\[{{O}_{2}}\]	\[MgO\]	\[Mg{{(OH)}_{2}}\]
(b) \[{{O}_{2}}\]	\[N{{a}_{2}}{{O}_{2}}\]	\[Mg\]	\[MgO\]
(c) \[{{O}_{2}}\]	\[N{{a}_{2}}O\]	\[MgO\]	\[Mg{{(OH)}_{2}}\]
(d) \[{{H}_{2}}O\]	\[{{O}_{2}}\]	\[Mg{{(OH)}_{2}}\]	\[MgO\]

Answer:

We know that Metallic hydroxides are formed when metal oxides are dissolved in water. \[\therefore \]\[N{{a}_{2}}O(Y)+{{H}_{2}}O\to 2NaOH\Rightarrow Y=N{{a}_{2}}O\] \[N{{a}_{2}}O\]is formed when sodium reacts with oxygen. \[\therefore \]\[4Na+{{O}_{2}}(X)\to 2N{{a}_{2}}O\Rightarrow X={{O}_{2}}\] \[\therefore \]\[2Mg+{{O}_{2}}\to 2MgO(Z)\Rightarrow Z=MgO\] \[\therefore \] \[MgO+{{H}_{2}}O\to Mg(OH)(K)\Rightarrow K=Mg{{(OH)}_{2}}\]