Question

The equilibrium reaction below has the Kc = 0.254 at 25°C. If the temperature of the system at equilibrium is decreased to 0°C, how and for what reason will the equilibrium shift? Also show and explain how and why the Kc value will change.

Answer 1

The equilibrium shifts towards reagents

Step-by-step explanation:

Is known
`Kc=([products])/([reagents])` rised to the power of their number of moles in the balanced reaction. When you have a system at equilibrium with Kc < 1, it means [products] < [reagents] and the system needs energy to react, so if you decrease tempeture the equilibrium shifts towards reagents and less products will be created.

This efect can be discribed with Van´t Hoff equation:
`ln((K1)/(K2)) =-(dH)/(R) ((1)/(T1) -(1)/(T2) )` where we can see that if we decrease temperature (this is T2<T1) in consecuense K2<K1 and reaction doesn´t happen.