Answer to Question #172585 in General Chemistry for sdasd

Question

Effect of adding NH4SCN

1. In a moment, you will be adding NH4SCN to your reaction system. Adding NH4SCN should affect the concentration of which species in the equilibrium reaction?
2. Should this speed up the forward reaction or the reverse reaction?
3. According to Le Chatelier’s principle, predict which way the reaction should shift (left or right)
4. Now to test your prediction – to test tube #2, add a few crystals of solid NH4SCN.
5. What do you observe happening? Report any color changes or other changes you observe. 

Answer 1

If the concentration of a substance is changed, the equilibrium will shift to minimise the effect of that change. If the concentration of a reactant is increased the equilibrium will shift in the direction of the reaction that uses the reactants, so that the reactant concentration decreases.

In a chemical equilibrium, the forward and reverse reactions occur at equal rates, and the concentrations of products and reactants remain constant. A catalyst speeds up the rate of a chemical reaction, but has no effect upon the equilibrium position for that reaction.

Adding additional reactant to a system will shift the equilibrium to the right, towards the side of the products.