The Effect of Concentration on the Rate of Reaction
Planning
AIM
To look at the change in concentration on the rate of reaction
BACKGROUND THEORY
The rate of reaction tells us how quickly a chemical reaction happens.
We can work it out after doing an experiment. We can measure how much
reactant is used up in a certain time or how quickly products are
formed. We then work out what 1/time taken is and that gives us the
rate.
The rate of the reaction can be affected by a number of things:
Concentration
Surface area
Temperature
Catalysts
The collision theory
The greater the surface area, the faster the rate of reaction. This is
because more atoms are exposed and ready to react.
The higher the temperature, the faster the rate of reaction. This is
because raising the temperature makes the particles collide more often
in a certain time and it makes it more likely that collisions will
result in a reaction.
Catalysts speed up chemical reactions therefore increase the rate of
reaction.
The collision theory is that the more collisions between particles in
a given time, the faster the reaction. This goes for all of the above
factors and is the basis for why reactions take place.
PRELIMINARY WORK
For our preliminary work, we decided the factor we were going to
investigate was how concentration affects the rate of reaction.
We used sodium thiosulphate (Na2 S2 O3) as our concentrated solution,
hydrochloric acid and water to carry out our experiment. We did the
experiment with two concentrations of sodium thiosulphate, 40gpl and
25gpl, to see which we would use for our main investigation.
On a two pieces of paper, we drew a cross and place a beaker on top of
the crosses. Into the beakers we poured 25cm3 sodium thiosulphate, the
40gpl solution in one and the 25gpl solution in the other. To each of
the solutions we added 5cm3 of hydrochloric acid and started timing.
These pebbles were picked out randomly. We took 100 pebbles from each end and measured their length using a ruler and used the shape chart to decide what shape the pebbles were. First we had go... ... middle of paper ... ... ehicle.
CL-, as the ions of H+ and OH- react to form H2O. These spectator ions
3. The beaker was filled with water and the metal was placed in the water.
How Amylase Concentration Affects the Rate of the Starch Concentration In this piece of coursework, I have to carry out an investigation to find out how amylase concentration affects the rate of starch. Enzymes are biological catalysts that speed up the chemical reaction that goes on inside living things. An enzyme acts on substrate and may do its job inside or outside the cells. However, the rate at which enzymes work are affected by the following factors/variables: Concentration:
Investigating the Effect of Concentration on the Rate of Diffusion Aim: To find out if concentration affects the rate of diffusion. Prediction: I predict that the higher the concentration of acid the faster the reaction will be. Hypothesis: Diffusion is the spreading out of a gas or liquid from an area of low concentration to another area where it has a lower concentration until the overall concentrations are balanced. The Hydrochloric acid (HCl) diffuses into the gelatine cube of which contains Sodium Hydroxide (NaOH), which is an alkali. When the Hydrochloric acid combines with the Sodium Hydroxide they form salt and water, which is neutral therefore turning the pink cube to clear.
Remove the metal object from the first beaker and insert it into the second one.
Plan 1. Collect 4 different sized beakers 2. Boil some water in the kettle 3. Pour 50ml into each beaker 4. After 1 minute check temperature 5.
It is important however to note that the NH4 and K ions are still in
Any remaining carbon is to be cleaned off the beaker so that the flame can easily heat the water. Exactly 100ml of water is to be used. The length of the wick on the spirit burner must be the same. The height of the burner from the beaker (the brick height) must be the same. The beaker must stay the same shape as well because if it is not the flame may have more surface area where to heat the water.
Start with the hot water and first measure the temperature. Record it. 8. Then pour 40 ml into the beaker. You can measure how much water was used by looking at the meniscus.
Use the thermometer to take the temperature of the water and then record it on your data sheet.
The Effect of Concentration of Hydrochloric Acid on the Rate of Reaction with Magnesium Aim: To investigate the effect of concentration of hydrochloric acid on the rate of reaction with magnesium Prediction: As the concentration of the hydrochloric acid increases, so will the rate of reaction Hypothesis: In a reaction, particles of two different reactants react together to form a product. The reaction only takes place on account of two things, if the particles collide, and if the collision has enough 'activation energy'. The two reactant particles, in this case magnesium particles and hydrochloric acid particles, must collide with each other on the correct 'collision course'. If this does not occur then no chemical reaction will take place. The reaction must also have enough energy, this can be affected by temperature, the more heat the particles have the faster they move and so the more energy therefore more chance of successful collisions.
First we placed the slide under the simple microscope and observed it at ten times magnification level. We each took turns looking. We then copied them as drawings into our Cornell notebooks. After that we changed the magnification to fifty times and observed the slide. We each took turns looking. We then copied what we saw into our Cornell notebooks. After that we changed the magnification level to sixty times and we each took turns looking at the slide. We then copied what we saw into our Cornell notebooks and sat down together. When we were all done drawing we spoke about what we seen and gave each other ideas on how to write our Lab Reports.
It is also important we keep the colour and size of the cross the same this will help keep the results fair for the experiment. Another thing we must do is to make sure that the beaker is completely clean and free of any water or any other substance before we attempt to start the next experiment.
The rate of reaction is how quickly or slowly reactants in chemical reactants turn into products. A low reaction rate is when the reaction takes a long time to take place; hence, a reaction that occurs quickly has a high reaction rate. A rate refers to how slow or quick the product is produced. It is possible to control the rate of chemical reactions and speed up or slow down the rate of chemical reactions by altering three main factors which are temperature, concentration and the surface area. When the temperature of the reactants increases, the molecules vibrate at a more intense speed therefore colliding with each other more frequently and with increased energy resulting in a greater rate of reaction. Accordingly, as the temperature decreases the molecules will move slower, colliding less frequently and with decreased energy resulting in the rate of reaction decreasing. Concentration is how much solute is dissolved into a solution and is also a factor that affects the rate of reaction. When the concentration is greater this means there is an increased amount of reactant atoms and molecules resulting in a higher chance that collisions between molecules will occur. A higher collision rate means a higher reaction rate. Consequently at lower concentrations there are reduced chances of the molecules colliding resulting in a lower reaction rate. The measurement of how much an area of a solid is exposed is called the surface area. The quicker a reaction will occur the more finely divided the solid is. For example, a powdered solid will usually have a greater rate of reaction in comparison to a solid lump that contains the same mass for it has a lower surface area than the powdered solid.