Gibbs energy of formation triangleG_(f)^(G) of MgO (s) and CO (g) at 1273 K and 2273 K are given below : triangleG_f[MgO (s)]= -941"kJ mol"^(-1)" at 1273 K" triangleG_f [CO (g)]=-439"kJ mol"^(-1)" at 1273 K" triangleG_f [MgO (s)] =-314"kJ mol"^(-1)" at 2273 K" triangleG_f[CO (g)] =-628"kJ mol"^(-1)" at 2273 K" On the basis of above data, predict the temperature at which carbon can be used as a reducing agent for MgO (s).

Gibbs energy of formation triangleG_(f)^(G) of MgO (s) and CO (g) at 1

1.	Gibbs energy of formation triangleG_(f)^(G) of MgO (s) and CO (g) at 1273 K and 2273 K are given below : triangleG_f[MgO (s)]= -941"kJ mol"^(-1)" at 1273 K" triangleG_f [CO (g)]=-439"kJ mol"^(-1)" at 1273 K" triangleG_f [MgO (s)] =-314"kJ mol"^(-1)" at 2273 K" triangleG_f[CO (g)] =-628"kJ mol"^(-1)" at 2273 K" On the basis of above data, predict the temperature at which carbon can be used as a reducing agent for MgO (s).
Answer» Solution :For the reaction, `MgO(s)+C(s) to Mg(s)+CO(g)` At 1273 K, `triangleG_(r)=triangleG_(r) [CO(g)]-triangleG_(f) [MgO(s)]=-439-(-941)"kJ mol"^(-1)=502"kJ mol"^(-1)`. At 2273 K, `triangleG_(r)=-628-(-314)kJ mol^(-1)=-314"kJ mol"^(-1)`. The TEMPERATURE is 2273 K.