Investigation Flashcards
What is the aim:
To find the concentration of electrolytes in an unidentified sports drink.
Background:
Chemical bonding refers to the force of attraction holding the atoms together in molecules and compounds. Ionic bonding refers to the chemical bonding between metals and non-metals. The metal atoms donates an electron/s to the non-metal. This forms the metal into a cation and non-metal into a anion. Electrolytes are substances when dissolved in water or melted they produce ions which can carry a charge. Higher the concentration of electrolytes more ions are produced hence there is higher conductivity. Electrolyte rich sports drinks are commonly used to replenish electrolytes lost through sweating. They help maintain hydration and support optimal muscle. Medical application for rehydration therapy. They help regulate nerve function, muscle contractions and ph balance.
Hypothesis:
As the concentration of potassium nitrate increases the conductivity of the solution will also increase. They are directly proportional to each other.
Variable
Independent: Concentration of Potassium Nitrate: (mol/l)
Dependent: Current in amps produced by each concentration of potassium nitrate. Conductivity of Potassium Nitrate(Different concentration).
Controlled Variables:
1.Amount of volts
2.Same volume of different concentrations of Potassium nitrate.
3.Current
Equipment:
1.Power Supply (0-12) Volts
2.Plate electrode system
3.Multimeter or ammeter
4.Electrical Leads
5.Beakers 6 100ml
6.Distilled Water 2Lw
7.Various 5 Concentration of Potassium Nitrate
8.An unidentified sports drink
Risk Assessment:
One risk working with electrical equipment such as the power supply and multimeter pose a risk of electric shock, if not handled properly to minimize this risk, ensure that all electrical equipment is properly grounded and in good working condition before use.
Another risk is the chemical exposure. Handling chemicals such as potassium nitrate solutions and electrolyte sports drinks involves chemical exposure, irritation or allergic reactions particularly if they come in contact with the skin, eyes or mucous membrane. To minimize this risk, wear appropriate protective clothing such as gloves, lab coat and safety glasses to avoid direct contact with chemicals.
Error Analysis:
There were several errors in our experiment. Our first error was contamination or cross contamination. This occurred when transferring the electrolyte solution and the metal plates. As we did not properly clean them before placing them in the next volume of differently concentration potassium nitrate. This can affect the conductivity reading leading to inaccurate results. Traces of higher concentrated potassium nitrate could lead to higher conductivity when measuring one with a lower concentration.
Our second error was that there is a consistent bias in the conductivity readings due to the improper calibration of the multimeter or systematic deviations from true values. This is a systematic error. The multimeter consistently read conductivity values higher or lower than the actual values across all measurements.
Method:
1.Wear safety glasses throughout the experiment.
2.Connect the plate electrode system to a 6 volt D.C power supply and ammeter.
3.Grab a 100ml beaker and pour 40ml of one of the concentrations of potassium nitrate into the beaker.
4.Turn on the power supply and multimeter and set the supply to 0 volts.
5.Carefully immerse the plate electrodes into the solution and set the power supply to 6 volts and allow the solution to stabilize.
6.Record the conductivity readings from the ammeter of the solution.
7. Carefully takeout the plate electrodes and rinse it with distilled water to prevent any cross contamination between the solutions. Gently wipe the plate electrodes with a paper towel.
8.Repeat steps 3 to 7 for the remaining concentrations of potassium nitrate solutions.
9.Pour 40ml of the unidentified sports drink into a 100ml beaker.
10.Immerse the plate electrode into the sports drink.
11.Set the power supply to 6 volts and allow the solution to stabilize for 1 minute.
12.Record the conductivity reading from the ammeter.
13.Record which concentration of potassium nitrate the conductivity readings were most similar.
Evaluation:
