An Experiment To Investigate The Relationship Between Surface Area and Rate Of Reaction
Introduction
The rate of reaction (reaction velocity) may be defined as the rate of change of concentration of a stated reactant or product. The rate of a reaction is found by measuring the amount of a reactant used up per unit of time or the amount of a product produced per unit of time. A reaction can be made to go faster or slower by changing a number of factors. In order for a reaction to occur certain things are necessary: particles must collide with each other and the collision must have enough energy for the reaction to occur. If this happens the original bonds are broken and new bonds are formed - so that new products are formed. Successful collisions (those with sufficient energy) can be increased (or decreased) by a number of factors.
These key variables consist of temperature, concentration, surface area and use of and type of a catalyst. To examine the relationship between the rate of reaction and surface area I must choose to vary only surface area keeping the other variables constant.
Surface area of solid - The surface area has an effect on the rate of reaction. If the solid has a large surface area per unit mass then there are more opportunities for collisions to occur between the solid and liquid. This is because there is more chance for collisions to occur. If the surface area per unit mass is small, collision can only occur with the outer atoms and is therefore limited. The diagram below illustrates this:
This relationship is proportional i.e. as one doubles so does the other. The temperature of the reaction - When the temperature is low, the particles in the reaction do not have much energy and move slowly so collision... ... middle of paper ...
...nes which can be explained by the fact that the surface area of the chips was constantly changing throughout the reaction, as it was reacted with the acid, and so did the surface area to volume ratio. Also as the marble was used up the reaction would slow, as there would be less marble remaining to react with the acid reducing the chances of a collision occurring. The evidence is sufficient to imply that my hypothesis is correct but I think to prove it successfully further evidence would be necessary.
I could have checked the rates of reactions I produced as a result of my experiment by carrying out a different test. If I had examined my results by doing a test measuring the mass change of the calcium carbonate I could have checked that I came up with sufficiently similar final rates of reaction, however I did not have time for this or to use a wider range of values.
surface area by taking a sample of 10 or 20 - this would give a good
It is important however to note that the NH4 and K ions are still in
Test tube A will have a piece of potato which is this size. Test tube
I think this because as the surface area increases, the speed of the reaction will increase therefore the gas will be produced faster. I believe this because most chemical reactions happen faster when there is more of the reactant to react with. When there is a larger surface area, there is more of the reactant available, which makes it easier for them to react together. Usually, when the surface area is doubled it will double the rate of reaction.
Height of sand, compression Flatten or compress the sand back to how it was, as accurately as possible, by using a flat surface. Research Question How does the height of the drop affect the depth of the sand? Hypothesis As the height of the drop for the ball increases, the measured depth of the sand will increase. This is because the ball will have more time to accelerate at 9.8ms-¹, and therefore have more momentum, creating a larger impact on the sand each time the height of the drop is raised.
will result in an increase in the speed of the rate of reaction it has
I have discovered that this is not the case. The sand is Interpretation and Evaluation: a.k.a In this experiment I found out that many different factors including. Concentration, Temperature and Surface Area affect the rate of reaction.
cloudy, to test this; I will place a piece of paper with a cross on
put it in a conical flask. I will put the flask on top of a piece of
In the example above 6000 bikes were fully completed. However, in the real world not all units will be fully completed at the end of an accounting period, some will only be partially completed. Equivalent units of production will look at how to convert these partially completed units into completed units for accounting purposes. Equivalent unit calculations are used at the end of a month, to prepare monthly production reports. They are also used at the end of the year to determine ending inventory values.
Productivity is the quantity of output formed by one unit of production input in a unit of time. Inputs used in the production of the goods and services are the major determinants of any country’s productivity they are also called factors of production. There are four major determinants of productivity of any country’s economy.
Hypothesis: As the ratio of surface area to volume of an object decreases the rate of heat loss from the object will also decrease. Objects with the same surface area to volume ratios loose heat at the same rate so long as there are not other variables involved.
Production Functions A production function in general, without specifying what kind, is related to the output of a production process which starts with the factors of production. Production functions are an integral part of explaining marginal products as well as allocative efficiency. There are different classifications for production functions, and what constitutes them, determined by the type of production. This article of the WIKI aims to focus on the Substitional production function, explaining what it is and means, as well as the limitations, of doing the same.
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.
k.e. = 1/2pv^3At, where A is the area of the surface and t is the time.