Chemistry practical: Concentration and preparation of solutions

solute

the substance that is dissolved

volume/volume % concentration

the volume is expressed in millilitres It can be used with liquid solutes

weight/weight % concentration

the weight of solute and the weight of solution are expressed in grams

use of density

we can use density to determine approximately the percent concentration of a solution

weight/ weight % concentration formula

weight of solute/ weight of solution *100

types of concentrations

weight/weight % concentration weight/volume % concentration volume/volume % concentration

normal concentration, normality

Normality is a type of concentration that shows the number of equivalents of a solute in one litre of solution which is used in analytical chemistry.

molar concentration formula

M= m1/Mr*V M= molarity Mr= relative molecular mass of solute V= volume of solution(l) m1= mass of solute (g)

mixing of solutions

Mixing of solutions is when a solution is prepared by mixing with another solution of the same solute or by diluting a more concentrated solution

Osmolarity (Osm/L)

Osmolarity is a type of concentration and is the number of osmoles in one litre of solution

Osmoles (osm)

Osmole is the number of moles of osmotic active particles

millimolar concentration (mM, mmol/L)

Shows the number of millimoles of a solute in 1 litre of solution and is used when the concentration of solute is low.

the amount of solutes can be expressed in what?

grams milligrams micrograms centimetre cubed moles

colligative properties

boiling point freezing point osmotic pressure vapour pressure

How can we determine the concentration of a solution

by measuring its density with areometer

molar concentration is used when measuring what?

colligative properties of solution

mass density (p)

mass density is the mass of 1L or 1mL of a given substance (solution). It's expressed in kg/m3 or g/mL

Density formula

mass of solution/volume of solution

Solution

solute + solvent

solution concentration

solution concentration is the amount of solute in a given amount of solution or solvent.

the amount of solute and solvent can be what?

the amount of solute and solvent can be 100g, 1mL 100mL 1000 mL

c1 c2 c3

the concentrations of the solutions we mix

An areometer consists of what?

An areometer consists of a tin of glass tube ending in a sphere

1 equivalent equals

1 mole of an ion divided to its charge.

Use of areometer

Areometers are used in brewing to test the strength of an acid in car batteries

dilution equation

C1V1=C2V2

molar concentration (Cm) formula

Cm= m1*1000/ m*Mr Cm= molar concentration m1= mass of solute m= mass of solvent Mr= relative molecular mass of solute

mixing equation

Cx= m1c1 +m2c2+ m3c3/ m1+m2+m3

Use of areometers in the lab

In lab practice they're used to determine the concentration of solutions

Number of moles

Mass / Mr

Solution

Solution is a mixture of 2 of more substances in a single liquid phase

Use of mg% or microgram %?

These types of concentrations are used in clinical labs in the blood and urine test and analysis of other biological liquid

When the amount of solute is small?

When the amount of solute is small, its concentration can be expressed as milligram percent concentration (mg%) or microgram percent concentration (yg%). The amount of solute is expressed in milligrams or micrograms and the amount of solution is 100g or 100mL.

areometer

areometer is an instrument based on Achimedes principle and is used to measure the relative density of liquids.

cross rule

cross rule is used when a solution is prepared from 2 solutions of one and the same solute different percent concentration

micromolar concentration

gives the number of micromoles of a solute in one litre of solution.

nanomolar concentration

gives the number of nanomoles of a solute in a litre of solution

relation between molar, millimolar, micromolar nanomolar and picomolar

mol/L= 10^3mmol/L= 10^6micromol/L= 10^9 nanomol/L= 10^12 pmol/L

molar concentration (M mol/L)

molar concentration is the number of moles of solute per litre of solution

molar concentration (Cm)

molar concentration shows the number of moles of a solute in 1000 grams of solvent

2 types of density used in practice

relative density (d) mass density(p)

relative density (d)

relative density is a digit that shows how much the weight of a given solution is bigger than the weight of an equal volume of water

weight/ volume % concentration

shows the weight of the solute in the total volume of solution. The volume is given in millilitres

solution density

solution density refers to the ratio between the weight and volume of a given solution

solvent

solvent is part of the solution that dissolves the solute

m1 m2 m3

the mass (in grams) of the solutions we mix