Maria examines a mixture that appears to be the same throughout. However, when she looks at a sample using a magnifying lens, sh
e can see small droplets of liquid surrounded by another liquid. Which conclusion best fits her observations? The mixture is a solution because it has the same appearance throughout the sample. The mixture is a suspension because it is composed of two different-appearing substances. The mixture is a heterogeneous mixture because one liquid is dissolved in the other. The mixture is a colloid because two different substances can be seen in a small sample.
Answer is: The mixture is a colloid because two different substances can be seen in a small sample.
Colloid is microscopically insoluble particles that are suspended throughout another substance. For example whipped cream and gelatin.
For example, in the presence of an emulsifying agent, a mixture of oil and water becomes a colloidal dispersion.
Colloidal dispersion otherwise colloid is a system, in which discrete particles, droplets or bubbles of a dispersed phase (in this case oil), whose size at least in one dimension is in the range from 1 to 1000 nm are distributed in the other, usually continuous phase - dispersion medium (in this case water) differing from the dispersed phase in composition or state of aggregation.
Catalyst increases the rate of the reaction without affecting the equilibrium position.
Catalyst increases the rate via lowering the activation energy of the reaction.
This can occur via passing the reaction in alternative pathway (changing the mechanism).
The activation energy is the difference in potential energies between the reactants and transition state (for the forward reaction) and it is the difference in potential energies between the products and transition state (for the reverse reaction).
in the presence of a catalyst, the activation energy is lowered by lowering the energy of the transition state, which is the rate-determining step, catalysts reduce the required energy of activation to allow a reaction to proceed and, in the case of a reversible reaction, reach equilibrium more rapidly.
with adding a catalyst, both the forward and reverse reaction rates will speed up equally, which allowing the system to reach equilibrium faster.
