Chapter 15
Concept of Solutions:
A solution is a homogeneous mixture composed of only one phase. In such a mixture, a solute is a substance dissolved in another substance, known as a solvent. The solvent does the dissolving.
A solution is a homogeneous mixture composed of only one phase. In such a mixture, a solute is a substance dissolved in another substance, known as a solvent. The solvent does the dissolving.
Polar and Non-Polar Solutions/Compounds:
Some elements have a greater tendency to attract electrons than the other ie they're more electronegative. So when in covalent moelcule a pair of less electronegative and a more electronegative element is present, the electrons shift from their mean position to slightly towards more electronegative. Thus the elements acquire slight charge. This is known as polar bond. The molecule so formed is known as polar molecule.
e.g. In HCl, Cl is more electronegative and attracts electron towards itself, Cl acquires slight negative charge and H acquires slight positive charge. Similarly in water, Oxygen acquires negative charge and hydrogen positive
So now we can define the required as Polar solvent are those solvents which are constituted of polar molecules. e.g. Water, HCl
Non polar solvents are those solvents which are made up of non polar molecules. e.g. Carbon Disulphide, Carbon tetrachloride
Some elements have a greater tendency to attract electrons than the other ie they're more electronegative. So when in covalent moelcule a pair of less electronegative and a more electronegative element is present, the electrons shift from their mean position to slightly towards more electronegative. Thus the elements acquire slight charge. This is known as polar bond. The molecule so formed is known as polar molecule.
e.g. In HCl, Cl is more electronegative and attracts electron towards itself, Cl acquires slight negative charge and H acquires slight positive charge. Similarly in water, Oxygen acquires negative charge and hydrogen positive
So now we can define the required as Polar solvent are those solvents which are constituted of polar molecules. e.g. Water, HCl
Non polar solvents are those solvents which are made up of non polar molecules. e.g. Carbon Disulphide, Carbon tetrachloride
Calculate Mass Percent:
Ordinary bleach is 5.25% NaOCl by mass, which means each 100 g of bleach contains 5.25 g NaOCl.
Mass percentage is one way of representing the concentration of an element in a compound or a component in a mixture. Mass percentage is calculated as the mass of a component divided by the total mass of the mixture, multiplied by 100%.
Ordinary bleach is 5.25% NaOCl by mass, which means each 100 g of bleach contains 5.25 g NaOCl.
Mass percentage is one way of representing the concentration of an element in a compound or a component in a mixture. Mass percentage is calculated as the mass of a component divided by the total mass of the mixture, multiplied by 100%.
Concentration and Molarity:
Molarity is an expression of the moles of solute (NaOH) per liter of solution (water). To work this problem, you need to be able to calculate the number of moles of sodium hydroxide (NaOH) and be able to convert cubic centimeters into liters.
Molarity is an expression of the moles of solute (NaOH) per liter of solution (water). To work this problem, you need to be able to calculate the number of moles of sodium hydroxide (NaOH) and be able to convert cubic centimeters into liters.
Calculate Dilutions:
CV=CV Dilution is the process of reducing the concentration of a solute in solution, usually simply by mixing with more solvent Example 1: You can add water to concentrated orange juice to dilute it until it reaches a concentration that is pleasant to drink. Example 2: Pure oxygen is too rich for us to breathe for long, leading to problems such as hyperoxia. In the air around us, oxygen is diluted naturally by the presence of nitrogen. Deep sea divers are harmed by nitrogen in the air, because deep under the sea gas pressures increase, and at higher pressures nitrogen causes an agonizing condition in divers called 'the bends'. For this reason, deep sea divers breathe oxygen diluted with helium rather than nitrogen. Solution Stoichiometric Problems:
Solution Stoichiometry deals with quantities in chemical reactions taking place in solutions. Once you have mastered this topic, you will be able to prepare solutions of desirable concentrations, carry out chemical reactions using correct amounts of solutions, predict amounts produced, and calculate yields. |
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