Molarity (M): The number of moles of solute per liter of solution. Molarity(M)=moles of soluteliters of solution\text{Molarity} (M) = \frac{\text{moles of solute}}{\text{liters of solution}}Molarity(M)=liters of solutionmoles of solute​

Molality (m): The number of moles of solute per kilogram of solvent. Molality(m)=moles of solutekilograms of solvent\text{Molality} (m) = \frac{\text{moles of solute}}{\text{kilograms of solvent}}Molality(m)=kilograms of solventmoles of solute​

Mass Percent (%): The mass of solute divided by the total mass of the solution, multiplied by 100. Mass Percent=(mass of solutetotal mass of solution)×100\text{Mass Percent} = \left( \frac{\text{mass of solute}}{\text{total mass of solution}} \right) \times 100Mass Percent=(total mass of solutionmass of solute​)×100

Volume Percent (%):The volume of solute divided by the total volume of the solution, multiplied by 100. Volume Percent=(volume of solutetotal volume of solution)×100\text{Volume Percent} = \left( \frac{\text{volume of solute}}{\text{total volume of solution}} \right) \times 100Volume Percent=(total volume of solutionvolume of solute​)×100

Parts Per Million (ppm): The mass of solute per million parts of the solution.ppm=(mass of solutemass of solution)×106\text{ppm} = \left( \frac{\text{mass of solute}}{\text{mass of solution}} \right) \times 10^6ppm=(mass of solutionmass of solute​)×106

Parts Per Billion (ppb):The mass of solute per billion parts of the solution.ppb=(mass of solutemass of solution)×109\text{ppb} = \left( \frac{\text{mass of solute}}{\text{mass of solution}} \right) \times 10^9ppb=(mass of solutionmass of solute​)×109

Normality (N):The number of equivalents of solute per liter of solution.Normality(N)=equivalents of soluteliters of solution\text{Normality} (N) = \frac{\text{equivalents of solute}}{\text{liters of solution}}Normality(N)=liters of solutionequivalents of solute​

Mole Fraction: The ratio of the number of moles of a component to the total number of moles of all components in the mixture. Mole Fraction(X)=moles of componenttotal moles of all components\text{Mole Fraction} (X) = \frac{\text{moles of component}}{\text{total moles of all components}}Mole Fraction(X)=total moles of all componentsmoles of component​

Uncontrolled
Ambient Temperature: Variations in ambient temperature may have a little impact on the response.
Vinegar Purity: Variations in vinegar composition may result in modest changes in acetic acid concentration.

Independent
The amount of NaOH solution added to vinegar.
Justification: Changing the volume of NaOH supplied allows you to determine how much is needed to neutralise the acetic acid in the vinegar.

Dependent
The quantity of NaOH needed to neutralise the vinegar's acetic acid content
Justification: This indicates the amount of acetic acid present in the vinegar.

Risks
Chemical Burns: Sodium hydroxide (NaOH), a strong base, can produce serious burns when it comes into contact with the skin or eyes. Always use protective gloves, goggles, and a lab coat when working with NaOH. In the event of contact, rinse thoroughly with lots of water and seek medical assistance as needed.

Inhalation of Fumes: Both acetic acid in vinegar and sodium hydroxide can emit fumes that can irritate the respiratory tract. Precaution: To reduce fume exposure, do the experiment in a well-ventilated environment or beneath a fumehood.

Spillage and Slips: Spilling NaOH or vinegar on the floor might provide a slippery surface and increase the danger of falling. Precaution: Clean up any spills promptly with suitable neutralising agents (e.g., vinegar for NaOH spills).

Glassware: Handling glassware, such as burettes and pipettes, can cause breakage, resulting in wounds or accidents. Precaution: Handle glassware with care, examine it for cracks before use, and dispose of broken glass appropriately in a designated receptacle.

Incorrect Chemical Disposal: Improper disposal of sodium hydroxide or acidic solutions can harm the environment and induce chemical reactions in waste systems. Precaution: Before disposal, neutralise the NaOH solution with a weak acid such as acetic acid, and adhere to local chemical waste disposal standards.

Skin Irritation from Acetic Acid: Although vinegar is typically harmless, strong acetic acid can cause skin irritation. Wear gloves when working with vinegar and avoid prolonged contact with the skin.

Possible errors
Endpoint Determination: The colour shift in phenolphthalein is subjective, and over-titration may occur if the endpoint is overlooked.
Concentration of NaOH: If the NaOH solution is not precisely made, the computed acetic acid concentration may be erroneous. Air Bubbles in the Burette: The presence of air bubbles might result in erroneous volume measurements.

Independent
The amount of sodium thiosulfate solution applied to the bleach.
Justification: The amount of thiosulfate used determines the amount of chlorine present, as it reacts with the iodine created.

Dependent
The chlorine concentration in bleach.
Justification: This is what is being measured using the titration method.

Controlled
The concentration of sodium thiosulfate solution is important for achieving consistent titration results. Bleach Volume: Each time bleach is titrated, a predetermined quantity is used. Indicator (Starch): Used to ensure consistent endpoint detection. Temperature of the Reaction: Temperature influences reaction speeds. Acid and KI concentrations should be consistent to guarantee correct iodine liberation.

Uncontrolled
Bleach Decomposition: The chlorine in bleach decomposes with time, particularly when exposed to light or heat, affecting concentration.
Ambient Conditions: Variations in ambient temperature may have a modest effect on the response.

Risks
Chemical Burns: Sulfuric acid and bleach must be handled with caution to avoid skin or eye contact.
Inhalation Hazards: Bleach fumes can be unpleasant, therefore operate in a well-ventilated environment or use a fume hood.

Possible errors
Missing the endpoint might result in over- or under-titration.
Concentration of Sodium Thiosulfate: Inaccuracies in making the thiosulfate solution may have an impact on the findings.
Bleach Decomposition: If the bleach sample is not analysed soon, it may decay and result in a lower concentration value.

Vinegar Volume: Each time vinegar is titrated, a specific amount must be used.

Phenolphthalein is used as an indicator to ensure consistent endpoint detection.

Temperature of the Reaction: Temperature influences reaction rates and acid dissociation, hence it must be maintained constant.

Titration Speed: To guarantee a regulated and consistent method of applying the titrant.

Justification
Titration is a well-known method of detecting acid content, and NaOH is a strong basic that totally neutralises acetic acid. Phenolphthalein was chosen because it shows a visible colour shift towards the terminus.

Justification
Redox titration using sodium thiosulfate is a standard method for detecting the concentration of oxidising chemicals such as hypochlorite. The colour shift with starch results in a distinct and crisp termination.