In this experiment I shall be look intoing how temperature affects the rate of reaction
Ratess of reaction
The Factors that affect the rate of reaction are temperature. surface country. concentration. accelerators. visible radiation and force per unit area
Surface country – Surface country is the sum of solid surface that is available for reaction – Only affects solids so this will non impact our experiment
– When the surface country increases the rate of reaction additions as there is more surface country for the atoms to work on. therefore. there are more hits per second
– Example: It is easier to illume a fire with little pieces of stick than utilizing big blocks of wood
Concentration – Concentration is the sum of molecules of a substance in a given volume
– Concentration affects solids. gases and liquid so this will impact our experiment – When the concentration increases the rate of reaction additions as there are more molecules present. therefore there are more hits between molecules ( Collision theory ) – Example: Zn reacts reasonably easy with dilute hydrochloric acid but when the acid is concentrated. the rate of reaction additions.
Catalysts – A accelerator is a substance which speeds up the rate of reaction without itself traveling undergoing any lasting chemical alteration – this means merely little sums of accelerators are needed to rush up reactions
– When a accelerator is involved in an experiment there is less energy needed for the reaction therefore there is more hits per 2nd – We will non be utilizing accelerators in our experiment – Example: Decomposing H peroxide solution at room temperature is really slow. but utilizing a little sum of manganese oxide greatly increases the reaction rate and O is given off quickly
– Light is a signifier of energy and it causes many chemical reactions to take topographic point.
– Light does non impact our experiment
– Example: Photosynthesis
Collision theory is used to explicate how different factors affect the rate of a chemical reaction. For a reaction to take topographic point the reactant particles must clash with each other with equal energy ( activation energy ) . this energy is used to interrupt the bonds between the atoms. If the atoms do non hold adequate energy they will resile off each other without responding. By increasing the temperature the atoms gain more energy and travel faster doing more hits per second.
These old experiments give us background information on rates of reaction:
Acid and limestone
CaCO3 ( s ) + 2HCL ( aq ) CaCl2 ( aq ) + H2O ( cubic decimeter ) + CO2 ( g )
Apparatus – Conical flask. hydrochloric acid. marble french friess. cotton wool and graduated tables
In this experiment we mix a certain mass of big marble french friess with a certain volume of hydrochloric acid in a conelike flask and utilize cotton wool to pin down the acid spray. As the C dioxide is given off from the flask. the mixture loses mass. this is measured and recorded every minute until the reaction is over. The experiment is repeated once more utilizing the same mass of marble french friess and the same volume of hydrochloric acid and the same temperature but alternatively utilizing little marble french friess. When we look at our consequences we find that the larger marble french friess take more clip to respond than the smaller marble french friess which show that as the surface country additions. the rate of reaction additions.
Decomposition of H peroxide solution
H2O2 ( aq ) 2H2O ( cubic decimeter ) + O2 ( g )
Apparatus – Conical flask. gas syringe. H peroxide solution and solid manganese oxide
In this experiment we foremost measure the clip taken for H peroxide to break up and bring forth 50cm3 of O at room temperature and without a accelerator. We use a gas syringe to mensurate the O given off. Then we repeat the experiment but alternatively add a little sum of solid manganese oxide to the H peroxide solution. When we look at our consequences we find that without the accelerator ( manganese oxide ) the reaction is really slow. but when we add the accelerator the decomposition is really fast and O is quickly given off which shows that accelerators increase the rate of reaction.
Sodium thiosulphate and hydrochloric acid
Na2S2O3 ( aq ) + 2HCL ( aq ) 2NaCl ( aq ) + SO2 ( g ) + S ( s ) + H2O ( cubic decimeter )
Apparatus – Sodium thiosulphate. hydrochloric acid. halt clock. a measuring cylinder and white paper with a black cross
In this experiment we vary the concentration of the Na thiosulphate. add it to a given volume of hydrochloric acid and clip how long it takes for the mixture to travel cloudy and the cross to vanish. When we look at our consequences we see that as we increase the concentration of Na thiosulphate the rate of reaction additions.
My anticipation is. as the temperature of the reaction mixture increases so to will the rate of reaction as at higher temperatures the atoms have more energy and will clash more hence increasing the rate of reaction. This is explained by the hit theory. The hit theory besides allows me to foretell that my clip against temperature graph will hold negative correlativity as the clip taken will diminish as the temperature increases. I besides predict this graph will be curved as the clip taken will non be straight relative to the temperature. I besides predict that as I increase the temperature of the mixture. the clip taken for the cross to vanish will diminish.
In my experiment I shall be look intoing the consequence of temperature on a reaction rate by responding Na thiosulphate in dilute hydrochloric acid as shown in the equation below
Sodium + hydrochloric Sodium + Sulphur + Sulphur + Water thiosulphate acid chloride dioxide
Na2S2O3 ( aq ) + 2HCL ( aq ) 2NaCl ( aq ) + SO2 ( g ) + S ( s ) + H2O ( cubic decimeter ) Sodium thiosulphate is a clear liquid and hydrochloric acid is a clear liquid. when they react together the solution turns cloudy due to the sulfur.
The reaction is exothermal as the energy required to interrupt the bonds is less than the energy needed to do new bonds.
• Conical flask
• Measuring cylinder
• Bunsen burner
• Stop clock
• White paper with a black cross
1. Measure out 10 cm3 of Na thiosulphate and 40cm3 of H2O into a flask. Measure out 5 cm3 of hydrochloric acid an a measurement cylinder 2. Heat the thiosulphate solution to the needed temperature utilizing a Bunsen burner 3. Add the acid and get down the halt clock. Twirl the flask to blend the solutions and put the solution on the white paper with a black cross 4. Look down at the cross and halt the clock and observe the clip taken when the cross has disappeared. Record the temperature of the mixture in the flask.
The variables we will necessitate to maintain invariable are
• The concentration of Na thiosulphate
• The concentration of hydrochloric acid
• The volume of hydrochloric acid
• The same coloring material of cross
• The same thickness of cross
• Look at the cross from the same tallness
The independent variable is the temperature. We will take 7 different recordings between 10o-70o We will make each recording 5 times and acquire an norm to do certain the consequences are accurate.
I will enter my consequences in the tabular array and do a clip against temperature and a 1/time against temperature graph as shown below