Chem - Titration of Bleach

Chem - Titration of Bleach - Titration of Bleach Objective:...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Titration of Bleach
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Objective: To find the molarity and percent mass of sodium hypochlorite in bleach. Theory: The process of titration involves the determining of an unknown concentration of a solution, by adding another solution of a known concentration, resulting in a chemical reaction. A chemical reaction can be defined as a process in which one or more substances are converted into other substances. A chemical reaction can usually be described with a chemical equation. Two reactants form a chemical equation. A chemical equation is a representation of a chemical reaction using the chemical formulas of the reactants and products. Both reactants and products can be categorized as aqueous, solid, liquid, or gas. Aqueous means a solution or a certain substance is soluble in water, and dissolved in water. It is represented by the letters “aq.” Solids are usually precipitates that form that are insoluble, represented by the letter “s.” A liquid is known as a substance in a fluid state of matter, and is represented by the letter “l.” Finally, a gas is a state of matter in which a substance takes on no particular shape or form, and is represented by the letter “g.” There are four different types of chemical reactions; they are synthesis, decomposition, single-replacement, and double-replacement. A synthesis reaction is a reaction in which two substances combine together to form a different substance. A decomposition reaction is simply the opposite, where a compound is broken down into parts. In a single replacement reaction, one element reacts with a compound and replaces another element in that compound. A double replacement reaction is known as a chemical reaction between two compounds where the positive ion of one compound is exchanged with the positive ion of another compound. In this particular experiment, the reaction can be classified as a double replacement reaction. The titration of sodium hypochlorite, NaClO, occurs through a series of reactions, after KI, starch, and HCl are all placed into the solution. Ultimately sodium hypochlorite is titrated by sodium thiosulfate. The three reactions involved in this experiment are: 1. 2H + (aq) + ClO - (aq) + 2I - (aq) → Cl - (aq) + I 2(aq) + H 2 O (l) 2. I 2(aq) + I - (aq) → I 3 - (aq) 3. I 3 - (aq) + 2S 2 O 3 -2 (aq) → 3I - (aq) + S 4 O 6 -2 (aq) This series of reactions shows that the S 2 O 3 -2 used to titrate actually reacts with the I 3 - formed in the second equation. Therefore, the amount of I 3 - is at a ratio to S 2 O 3 -2 (thiosulfate) of 1:2. The I 3 - is at a ratio of 1:1 with the I 2. Finally, the I 2 is at a ratio of 1:1 with the ClO - found in the first reaction. Since ClO - is a constituent of NaClO, it can be noted that for every 1 mole of ClO - , one mole of Na + exists, which means that there is one mole of NaClO for every 1 mole of ClO - indicating a 1:1 ratio between the two. In determining a concentration, molarity is used, which is represented by the capital letter “M.” Molarity can be described as the ratio of moles of a substance, to liters of the total
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/25/2012 for the course CHEM 4385 taught by Professor Staff during the Fall '11 term at Texas State.

Page1 / 7

Chem - Titration of Bleach - Titration of Bleach Objective:...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online