SAMPLE A - <span>pure substance.
</span>SAMPLE B - <span>homogeneous mixture.
</span>SAMPLE C - <span>heterogeneous mixture.
</span>Pure substance - <span>constant composition and properties.</span>
Homogeneous mixture - same uniform appearance and composition.
Heterogeneous mixture - <span>not </span>uniform<span> in composition, two phases (liquid and dust).
</span>
I think the one that cause the equilibrium to shift would be :
3. adding a noble gas
Adding the noble gas will add more concentration to the KNO3, which will create different amount of equilibrium
hope this helps
