11-2 Rates of reaction homework - 18/3/08
March 18, 2008 — Mr ChittendenYear 11 Set 2 Students! 
Here are your homework questions. Please leave your first name and initial, and post DETAILED answers. I will not reveal them until our next lesson, so you can’t copy anyone elses!
A chemist investigates the reaction of marble chips with hydrochloric acid. He measures the time taken for 100 cubic centimetres of carbon dioxide gas to be formed.
1) How might he collect the gas formed?
At 60 degrees C, with a 1M solution of acid, and using 1g of marble chips, the reaction takes 13.7 seconds
For each of the following changes, describe the a) effect on time taken, b) effect on rate, and c) explain why this happens, using collision theory
2) With crushed marble instead of chips
3) With a more dilute acid solution
4) At a lower temperature
March 18, 2008 at 1:31 pm
1)Collects the gas in a test tube with a plunger in it so the gas doesn’t escape. It is measured cm3.
2)With crused marble instead of chips the rate of reaction will happen faster because it is broken down into more particles which are full of energy so there would be more collisions meaning more effective reactions. Therefore, the time taken would be less because there is loads of particle full of energy ready to collide with each other for an effect reaction.
3)The more dilute the solution, the longer it will take to react. (not sure)
4)The lower the temperature, the more time taken for it to react. This is because the hotter the particles are the more energy they have. If they are not very hot then they will not move around as fast. Therefore, have less chance of colliding with each other. So the rate of reaction is slow because of this. They need to collide for the reaction to take place so if they have less energy they have less chance of colliding.
March 19, 2008 at 7:14 pm
1) The chemist would use a gas syringe to collect the gas
2a) If the chemist uses the same investigation but uses crushed marble instead the time taken would be quicker because the particles are smaller,
2b)the rate would be faster because the particlesa are smaller and can collide quicker
2c) when the marble is crushed it is quicker because there are more particles to collide qith each other making it faster.
3a) If the chemist uses a more dilute solution the time taken would be slower because it is not as strong as a concentrated solution
3b) The rate would be slower if a dilute solution was used.
3c) the rate would be slower because there is less particles to collide with each other.
4a) if the chemist used a lower temperature the time taken would be slower.
4b) The rate would be slower when using a lowr temperature
4c) the rate would be slower because the particles have less energy meaning that there are less collisions.
March 19, 2008 at 8:48 pm
(Continued on from 18th march, accidentally sent the message)
4) A lower temperature will greatly lengthen the time taken for the reaction to happen and the rate will therefore be slower
March 19, 2008 at 9:31 pm
A chemist investigates the reaction of marble chips with hydrochloric acid. He measures the time taken for 100 cubic centimetres of carbon dioxide gas to be formed.
1) How might he collect the gas formed?
he might collect this gas in a sealed measuring cylinder, with the gas travelling into the measuring cylinder through a tube from the test tube, with the hydrochloric acid in it.
At 60 degrees C, with a 1M solution of acid, and using 1g of marble chips, the reaction takes 13.7 seconds
For each of the following changes, describe the
a) effect on time taken,
b) effect on rate,
c) explain why this happens, using collision theory
2) With crushed marble instead of chips
With the marble crushed the time taken would increase, meaning the rate of reaction would increase, this happens because there are more collisions happening every second
3) With a more dilute acid solution
With a more dilute acid solution the time taken would increase, and the rate of reaction would dercrease, this happens because there are alot less collisions happening every second
4) At a lower temperature
At a lower temperature the time taken would increase, meaning the rate of reaction would decrease, because there are less collisions happening every second because the particles are not moving around as fast.
March 20, 2008 at 8:40 am
1, he might collect it in a gas syringe
2, the rate would increase because the surface area would be bigger and there would be more effective collisions
3, the rate would decrease and there would be less collisions. it would take a longer time.
4, the rate would decrease and their would be less effective collisions. it would also take a longer time.
March 20, 2008 at 9:04 am
1) using a gas syringe, so the gas can be measured.
2) using crushed marble instead of chips would increase the time taken, the rate would happen much quicker too. this is because the reaction needs the correct orientation and activation energy so more particles would hit each other in order for the reaction to wwork quicker.
3) the reaction would be slower if a dilute acid solution would work because there is not enough activation energy for the rate of reaction to happen.
4) if a lower temperature is used the rate of reaction would be low and the time for this to happen would be slow.
March 20, 2008 at 9:09 am
1) He might collect the gas formed by using a……….
2) a) the time taken would be shorter
b) the rate of reaction would be quicker
c) this happens because there are more particles, so there is a greater chance of the particles hitting, and more often.
3) a) the time taken would increase
b) the rate of reaction would be slower
c) this happens because there is a lower concentration of the patrciles, so the collisions and reactions are less likely to happen.
4) a) the time taken would increase
b) the rate of reaction would be slower
c) this happens because the particles are moving slower, and will collide less frequently. Also, becuase of the lower temperature, some patricles might not have enough activation energy for the reaction.
March 20, 2008 at 1:19 pm
1. He might collect the gas in a tube that leads to a test tube.
2a. Does not take as long.
b. High rate of reaction.
c.
3a. Takes longer.
b. Low rate of reaction.
c.
4a. Takes longer.
b. Low rate of reaction.
c.
March 20, 2008 at 9:30 pm
1) To collect the gas formed he could use a syringe.
2a) The time taken would increase as there are more particles.
b) The rate of the reaction would increase.
c)There are more collisions between the particles.
3a)The time taken would increase as there is more particles and would take longer to collide.
b)The rate of reaction would decrease.
c) Higher concentration would increase the collisions.
4a) At a lower temperate the time taken would decrease because the particles will move slower.
b)The rate of reaction would decrease.
c) The particles will not have as much collisions and will be slower.
March 21, 2008 at 11:36 am
A chemist investigates the reaction of marble chips with hydrochloric acid. He measures the time taken for 100 cubic centimetres of carbon dioxide gas to be formed.
1) How might he collect the gas formed? stick a testtube with sa substance such as water or hydrochloric acid over the top.
At 60 degrees C, with a 1M solution of acid, and using 1g of marble chips, the reaction takes 13.7 seconds
For each of the following changes, describe the a) effect on time taken, b) effect on rate, and c) explain why this happens, using collision theory
2) With crushed marble instead of chips the time and rate would increase as there would be more collisions because there would be more particles to collide and there for it would take less time to react
3) With a more dilute acid solution the rate of reaction would increase there would be more collisions between particles. however it would take longer for the particles to pair up so the time taken to react would be longer
4) At a lower temperature the rate of reaction would be less as the particles have less energy for collisions
so they would have less effective collisions
March 23, 2008 at 10:50 am
1.He could collect the carbon dioxide gas in a cylinder. ?
2. The time to react is quicker because it is hotter so the particles collide with each other faster. The rate is faster because there are a high amount of reactants forming. This happens because the particles get so hot they move quicker and therefore collide with each other more causing more collisions making the reaction faster, causing the time and rate to quicken. 2. Crushed marble instead of chips wouold be much quicker because the particles are already broken down so will react quicker. The rate will increase because more reactants are forming products, and collisions will be more effective making the process quicker. 3.Using a more dilate solution would effect the time it would take longer because the solution is less concentrated and the rate of the reaction will slow because it will take longer for the reactants to form into products.4. At a lower temperature the process will slow because the particles will not move as fast which gives them less chance to collide with each other, the time taken will decrease and be much slower and the rate of the reaction will be slow because of the particles not colliding so much.
March 24, 2008 at 7:08 pm
1) measure using a rubber tubing connected to the flask with the reactants and also connected to the gas syringe.
2) the rate of reaction will be faster due to a larger surface area
3)the rate will be slower because there will be less particles resulting in less collisions.
4)the rate will be slower because the particles have less energy meaning they won’t collide as often and less of the collisions are effective.
March 25, 2008 at 8:59 pm
crushed marble insead of chips- decrease time taken, increase rate because the particles can mix quicker in powder because they are broken down.
more dilute acid solution- increase time taken decrease rate (less acid less quickly the particles are broken down?)
lower temp- increase time taken decrease rate- the higher the temperature the quicker the rate
March 25, 2008 at 9:26 pm
1) in a test tube
2)a. longer b. decrease c. ?
3) a.shorter b. increase c. it is more acidic, reaction is quicker
4)longer b.decrease c. lower tempertaure, so it will take longer
March 26, 2008 at 5:11 pm
1.)gas syringe/gas cylinder
2a.)it is faster
b.)more products
c.)more collisions because there is more products
3a.)it takes longer
b.)the rate decreases because less energy
c.)less collisions
4a.)it takes longer
b.)the rate decreaces because of lower temperature
c.)not as many collisions because there is less energy
March 26, 2008 at 7:49 pm
1. Gas could be collected through a gas syringe
2. with crushed marble the reaction will happen quicker, the quicker rate and this all happens because there are more particles in the solution and so the particles are more likely to make contact
3. with a more dilute solution of acid the reaction will happen much slower, the rates will therefore be slower and this happens because there is less solution for the particles to be broken down
4. The lower the temperature the slower the reaction and therefore the slower the rate, this is because less energy to go round and so there are less collisions
March 30, 2008 at 10:37 am
1)With a gas Syringe
2)a) The time would be quicker.B)C)More collisions happen because the marble is crushed…
3)a) The time would be slower. B) The rate would be higher.C) There would be less collisions due to there being a dilute solution which makes the reactions slower .
4)a)Slower.B) The rate would be less.C) There would be less collisions because there is less heat to speed up the reaction.
March 30, 2008 at 3:27 pm
1) How might he collect the gas formed?
in a gas cylinder
a) effect on time taken - the rate would go up because they will collide more
b) effect on rate - the rate would go up because they will collide more
c) explain why this happens, using collision theory
2) With crushed marble instead of chips - if there crushed they’ll be smaller so they will collide more often.
3) With a more dilute acid solution- ????
4) At a lower temperature- the rate of the reaction would be slower.
March 30, 2008 at 5:32 pm
A chemist investigates the reaction of marble chips with hydrochloric acid. He measures the time taken for 100 cubic centimetres of carbon dioxide gas to be formed.
1) How might he collect the gas formed?
A gas cylinder.
At 60 degrees C, with a 1M solution of acid, and using 1g of marble chips, the reaction takes 13.7 seconds
For each of the following changes, describe the a) effect on time taken, b) effect on rate, and c) explain why this happens, using collision theory
2) With crushed marble instead of chips
a) it increases
b) it increases
c) the time taken is increased meaning they collide more with more energy.
3) With a more dilute acid solution
a) ?
b) ?
c) ?
4) At a lower temperature
a) Decrease
b) decrease
c) because they are moving slower with less energy meaning, less collisions
March 30, 2008 at 9:15 pm
1) collected in a syringe so the gas cannot escape.
2)With crushed marble the reaction time would decrease as the particles are freer so would collide quicker meaning the rate is quicker.
3)The more dilute a solution the longer the time taken and the longer the rate because the react better when they are acidic.So, the less acidic the less collisions.
4)The lower the temperature, the longer the time taken and the slower the rate.This is because there is less activation energy meaning less chance of the particles colliding.
March 30, 2008 at 9:27 pm
A chemist investigates the reaction of marble chips with hydrochloric acid. He measures the time taken for 100 cubic centimetres of carbon dioxide gas to be formed.
1) How might he collect the gas formed?
gas syrine
At 60 degrees C, with a 1M solution of acid, and using 1g of marble chips, the reaction takes 13.7 seconds
For each of the following changes, describe the
a) effect on time taken - increases
b) effect on rate - quicker
c) explain why this happens, using collision theory -
2) With crushed marble instead of chips - the reaction will be quicker becuase there will be a bigger surface area for the acid to work on.
3) With a more dilute acid solution - it will take longer to prodice the gas.
4) At a lower temperature - it will take longer, becuase reactions are quicker when they are at a higer temperture, therefor it will be slower becuase it is lower.
March 31, 2008 at 6:22 am
1. He could collect the gas formed In a test tube.
2a. The time taken would decrease.
2b. The rate of reaction would increase.
2c.
3a. The time taken would decrease.
3b. The rate of reaction would increase as the concentration increases.
3c. This is because more particles will collide.
4a. The time taken would increase.
4b. The rate of reaction would decrease.
4c .
March 31, 2008 at 8:06 pm
A chemist investigates the reaction of marble chips with hydrochloric acid. He measures the time taken for 100 cubic centimeters of carbon dioxide gas to be formed.
1) How might he collect the gas formed?
Using a glass syringe
At 60 degrees C, with a 1M solution of acid, and using 1g of marble chips, the reaction takes 13.7 seconds
For each of the following changes, describe the a) effect on time taken, b) effect on rate, and c) explain why this happens, using collision theory
2) With crushed marble instead of chips
More particles are exposed…..?
3) With a more dilute acid solution
a) the time taken would be higher because there are less particles resulting in less collisions however because there are less particles it would take less time for them to react
b) the rate of reactions would decrease because there is less energy, so there would be less collisions taking place and they would be less efficient
c) this happens because the lower the concentration the more time the reaction will take, which means that less particles will collide less often because there will be less energy, resulting with less effective collisions and reactions
4) At a lower temperature
a) the rate of time would be higher because there would be less energy
b)the effect on the rate would be that reactions decrease because there is less energy, so there would be less collisions taking place and they would be less efficient
c) the lower the temperature, the less energy the particles have, so they would collide less often and so the collisions would be less effective
April 2, 2008 at 8:16 am
1)
a gas syringe to collect the gas
2a)
it will be quicker because the particles are smaller,
2b)
the rate would be faster because the particles are smaller and can collide quicker
2c)
when the marble is crushed it is quicker because the particles collide more with each other making it faster.
3a)
the time taken would be slower because it is not as strong as a concentrated solution
3b)
The rate would be slower if a dilute solution was used.
3c)
it will be slower because there is less particles to collide with each other.
4a)
if the chemist used a lower temperature the time taken would be slower.
4b)
it will be slower when using a lower temperature
4c)
the rate would be slower because the particles have less energy meaning that there are less collisions.