Investigate how the change in concentration affects the rate of
reaction between sodium thiosulphate and hydrochloric acid
Introduction
I am trying to find out how the change in concentration affects the
rate of reaction between sodium thiosulphate and hydrochloric acid.
I predict that the higher the concentration of sodium of thiosulphate,
the quicker the rate of reaction will be between the two substances.
The scientific reason for my prediction is due to the collision
theory.
The collision theory is, that in order for chemicals to react they
must come into contact with each other (collide). However, not all
collisions result in chemical reactions as sometimes the particles
just bounce off each other. The particles must have sufficient energy
when they collide to react. If you increase the number of collisions,
you increase the rate of reaction. Therefore, a higher concentration
means a greater number of collisions.
Diagram
Preliminary Testing
This is the word equation for the reaction between the two substances:
Sodium + Hydrochloric Sodium + Sulphur
+ Sulphur + Water
Thiosulphate Acid Chloride
Dioxide
Na2S2O3 + HCl NaCl
+ SO2 + S + H2O
( aq ) + ( aq ) (
aq ) + ( g ) + ( s ) + ( l )
Before I start the investigation, by having preliminary tests I can
find a volume of each solution that I can use where I am able to
complete the investigation in a reasonable period of time. When I am
undergoing my experiment I will be making one variable. By changing
the concentration of sodium thiosulphate, this is done by adding water
to the solution. As I change the amount of water I put into the
solution the concentration of it is changing. The more water that is
put into the solution the weaker the concentration will become.
To get my preliminary results I set up the experiment as above in the
diagram section, and you use different amounts of the solutions.
Use a burette to measure the amounts of the solutions needed, and put
them into separate beakers. Using a funnel at the top of the burette
to pout the solution into. After firstly using a measuring cylinder to
measure the solution.
Use a stopwatch to time how long it takes for the cross underneath the
conical flask to disappear, as the solutions are mixed together. As
the reaction turns the two colourless liquids, into a milky colour
afterwards.
Repeat the procedure with different amounts of the solutions, working
out the best amounts that I could use for experiment.
These are the results that I received:
------------------------------------------------------------------------
Amount of H2O Amount of sodium Amount of hydrochloric Time Taken
this is the best volume to use as it is about ¾ of a test tube full,
We then took 1ml of the 0.1% solution from test tube 2 using the glucose pipette and added it to test tube 3, we then used the H2O pipette and added 9ml of H2O into test tube 3 creating 10ml of 0.01% solution.
CL-, as the ions of H+ and OH- react to form H2O. These spectator ions
We were then to make a base solution of 0.7 M NaOH. In order to standardize
· Rinse out mixture in flask and leave water running to get rid of the
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.
The Effect of Solute Concentration on the Rate of Osmosis Aim: To test and observe how the concentration gradient between a potato and water & sugar solution will affect the rate of osmosis. Introduction: Osmosis is defined as, diffusion, or net movement, of free water molecules from high to low concentration through a semi-permeable membrane. When a substance, such as sugar (which we will be using in the experiment we are about to analyse), dissolves in water, it attracts free water molecules to itself, and in doing so, stops them from moving freely. The effect of this, is that the concentration of (free) water molecules in that environment goes down. There are less free water molecules, and therefore less water molecules to pass across a semi-permeable membrane, through which sugar molecules and other molecules attached to them are too big to diffuse across with ease.
In my experiment, I will use an overall volume of 50 cm³ of 2moles of
* We would have to leave one end open to fill it up with the different
It is important however to note that the NH4 and K ions are still in
Flight is one of the most important achievements of mankind. We owe this achievement to the invention of the airfoil and understanding the physics that allow it to lift enormous weights into the sky.
b. Drop Calculations Vol/Number of Drops. 1mL/23Drops =.034mL /drop VII. Conclusion Unlike other labs, this lab allows for the most precise titration. results possible.
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.