Why some reactions are slow?

Concentration: If there is more of a substance in a system, there is a greater chance that molecules will collide and speed up the rate of the reaction. If there is less of something, there will be fewer collisions and the reaction will probably happen at a slower speed.

Why are some reactions faster than others?

Usually reactions speed up with increasing temperature. Physical state of reactants. Powders react faster than blocks – greater surface area and since the reaction occurs at the surface we get a faster rate. The presence (and concentration/physical form) of a catalyst (or inhibitor).

What type of reactions are slow?

Chemical reactions that occur very slowly and can take a long time for completion are called slow reactions. Usually covalent compounds are involved in slow reactions. Some reactions can take days, weeks and months to complete; they are called very slow reactions.

Why are reactions fast or slow?

The frequency of collisions: The more often molecules collide with each other, the faster the reaction proceeds. The energy of collisions: The more forcefully molecules collide with each other, the more likely they are to react, and the faster the reaction proceeds.

Why is rate of reaction faster at the beginning?

This is largely to do with how much of the reactants are present. As a result there will be more successful collisions between the reactant particles. The more successful collisions, the faster the reaction will be.

What makes a reaction slow or fast?

So, if there is a higher concentration of particles, then there should be more collisions in a given amount of time, and the reaction should go faster. In other words, the reaction will go faster only if we increase the concentration of particles that take part in the slow step.

What makes a reaction go slower or faster?

Also, if Page 3 more particles are available to react, the reaction will happen faster. To slow down a reaction, you need to do the opposite. When you heat a substance, its particles move faster. Faster-moving particles have more energy, which helps reactants get over the activation energy barrier more quickly.

Which reaction is faster Why?

Reactions in phases that easily mix, such as gases and liquids, occur much faster than reactions between solids. The extent of mixing of the reactants influences the frequency of molecular collisions – if reactants are more thoroughly mixed, the molecules will collide more often and thus react faster.

What makes a faster reaction rate?

Temperature. Usually reactions speed up with increasing temperature (“100C rise doubles rate”). Powders react faster than blocks – greater surface area and since the reaction occurs at the surface we get a faster rate. The presence (and concentration/physical form) of a catalyst (or inhibitor).

What affects the speed of a reaction?

Reactant concentration, the physical state of the reactants, and surface area, temperature, and the presence of a catalyst are the four main factors that affect reaction rate.

Why are reaction rates typically faster at the beginning and progressively slow down?