please help me with my homework i cant understand it at all?

Question

1. the speed of the reaction depends on the reaction conditions describe how each of the following affects the speed of a reaction

a particle size of reactants
b concentration of the reactants
c tempreature of the reactants

Please help

cpkid

Answer 1

im not doing your homework for you... but read this for more info...http://en.wikipedia.org/wiki/Chemical_reaction

What the question is asking (to my interpretation) is if the temperature was increased (or decreased) how would that effect the speed of a reaction? and so on..

i.e... sugar in water... if its hot water it dissolves faster... if its cold.. well, go test it out..

concentration... such as the more of something (or less) how does that effect how fast/slow something reacts..

particle size again.. if its something large, it'll take longer to break down than something small.. take sugar again, a grain of sugar, compared to a lump..which will dissolve faster??

Answer 2

a. Particle size: the smaller the particles the greater surface area. The reaction cannot proceed unless the reactants contact each other. Smaller partcles/greater surface area allow more of the reactants to come into contact for a given mass of them; hence faster reaction.
b. The more concentrated the reactants the less space between molecules of them and the more likely are they to come into contact with each other; hence the faster the reaction.
c. The higher the temperature the more energy will the molecules have and the faster the reactants will move in solution and are thus more likely to collide with each other - hence faster reaction.

When I learnt my chemistry this was all explained by my teacher; were you listening in the class or did you not understand it? If you didn't understand it then talk to your teacher - teachers are human and would rather you did that than write gibberish or give up.

Answer 3

a).
Particle Size.
When particles are large there is less surface area for the reactant to come into contact. So particles are made as small as possible so there is a large surface for reactant contact.
NB Think of a cube of wood. it has six surfaces each say 4cm^2 of surface.. So there is 24 cm^2 of surface area. Now if that same bloack of wood is cut into two cuboids, there are now two further surfaces exposed, but the volume and the original surface area have not altered. So there is 24cm^2 + (2 x 4cm^2) = 32 cm^2 of surface - the surface area has increased, allowing more contact with the given volume.

b)
Concentration.
In a given volume to increase the concentration there are more reactant particles, and they are closer together. Conversely to decrease the concentration (dilution) there are less reactant particles, so they are not a close together.

c).
Temperature.
Increasing the temperature gives the reactant particles more kinetic energy - they move about faster.In moving about faster the reactants have a greater change of a collision. In colliding, they may 'bounce' off one another, and not react, but they may also have a successful collision and react together.

NB for b) & c) think of a disco, you are all in a room of given size(volume). The more people (concentration) the closer you are all together. As the disco gets going you all become hot (temperature) and are more likely to bump into one another and/or change partners (react).

Answer 4

a) smaller particle sizes will increase the speed of reaction, because the reaction takes place at the surface of the reagent and increasing the particle sizes makes more surface available.

b) greater concentration of reactants will increase the speed of a reaction, because it effectively forces the chemicals into closer contact with each other, which speeds up the reaction.

c) increased temperature will usually increase the speed of a reaction, as you are supplying additional energy, in the form of heat.

The increased speed of the reaction should not affect the end point which will be when one of the reagents is consumed or the reaction reaches an equilibrium point.

Answer 5

A.ok particle size is easy the bigger the particles the more likely they are of hitting each other with the right amount of activation energy.
B.this means how much of the seactant is in the solutiong which then again helps if there is more because there more likely to collide with the right amount of activation energy.
C.the higher the tempreature the more the particles in the solution vibrate making then collide more often and with a bigger chance of having enough activation energy.

by the way use activation energy alot its good.

Answer 6

a) larger partical sizes would lover the speed of a reaction. this is because they are more stable, and would have less of a chance of interacting with each other than smaller particals

b) higher concentrations of reactants means that there are more particals. if you have more particals then you will have a greater chance of reactions - therefore higher concentrations means that the speed of reaction will be faster

c) partical mobility depends on their kenetic (movement) energy. this is derived from temperature. if you have a higher temperature the particals will have a greater kinetic energy, therefore they will be moving around more, and have a greater chance of 'bumping' in to each other. this will speed up the reaction process. therefore, higher the temperature, the faster the reaction

Answer 7

you cant just ask people to do your homework. it's given so you can practice what you've learned and if you don't understand then you need to get help at school, ask your teacher to explain it more in detail.

Answer 8

don't know about a
B- if there is more of something blocking somethings way, it slows it down
C- usually if something is cold it will move more slowly and if it's hot it will move more quickly