CHEMISTRY EXPERIMENT.

FIRST THING'S FIRST :

• Wear your safety glasses.
• Put on your lab coat.

TITLE:

WE ARE LOOKING AT THE FOLLOWING REACTION:

• HCL + Na2S2O5➡️NaCl+So2+ S⬇️+ H2O

⬇️means precipitate.
2.
CHEMISTRY
cause (a substance) to be deposited in solid form from a solution.
"cell proteins were then precipitated and washed in 10% trichloroacetic acid"

REACTANTS
hydrochloric acid
Sodium thiosulfate

PRODUCTS
sodium chloride(table salt)
Sulfur dioxide gas
Sulfur
Water

Variables
The only thing we varied was the amount of sodium thiosulfate

Constants.
We kept the following constant:
Temperature
Amount of water
Volume of concentration of HCL

What will the effect of increasing the concentration of sodium thiosulfate be on how fast the reaction takes place ?
The rate of the reaction will be faster.

COLLECT YOUR APPARATUS.

APPARATUS

• Conical flask
• Graduated cylinder
• Beaker
• White tile /page
• Spatula, electric balance.

Chemicals

• Sodium thiosulfate crystals.
• Hydrochloric acid.
• Water

PROCEDURE

measure 100cm3 of water into the graduated cylinder.

POUR THE WATER INTO THE CONICAL FLASK TO MAKE IT EASIER TO DISSOLVE

Measure out 0.5g of sodium thiosulfate.

Measure 10cm3 of hydrochloric acid in a smaller graduated cylinder.

Add the thiosulfate crystals into the water in the conical flask.

Wait until the sodium thiosulfate crystals are completely dissolved in the water

Place the conical flask with the dissolved sodium thiosulfate crystals onto the white page over the marked 'x'

Add the 10cm3 of HCL to the conical flask.

Time how long it takes until you can't see the 'x' on the white page anymore and the mixture goes cloudy.

Record results

Change all of your results into seconds and put them as a fraction eg:1/149=0.0149

Draw a graph of your results. You may have to use a line of best fit.

WASH UP!

The more sodium thiosulfate crystals added the faster the reaction will be.

Alice Clarke
4L