Biomedical Lab prelab Cards

Absorbance

Absorbance. Units or Optical density​,

Absorbance Units known as

AU or OD

Specfic gravity

dimensionless quantity

What Units to use for specfic gravity

Use density units density for calculations

Example of units to use

grams per centimeter cubed (g/cm3) or kilograms per meter cubed (kg/m3)

When is something unitless

ratio of quantities. all units cancel out

dont have true or expresssed units

where do derevied units come from

multiplying,dividing and powering base units

area unit

square meter (m²)

area units used in lab

m² and cm²

volume units

cubic meter (m³)

volume units used in lab

mL and L

speed/velocity units

meter per second (m/s)

speed/velocity units used in lab

m/s, moles/s, millimoles/s

amount of substance concentration unit

moles per cubic meter (mol/m³)

amount of substance concentration unit in lab

molarity (M), mM, nM

temp in unit

degree celicus (c degree sign)

temp in unit in lab

C and F

mass density unit

kilogram per cubic meter (kg/m³)

mass density unit in lab

g/mL

activity of enezyme in unitsAb

katal (one mole per sec)

activity of enezyme units used in lab

moles/time, mMoles/time

absorbance unit

-dont have true unit

other ways to say absorbance

absorance. units or optical density

absorbance abbervation

AU or OD or no units

specfic gravity

-dont have true unit

what does specfic gravity measure

dimensionless quantity

specfic gravity units used in lab

density units if ur dealing with density

OR

grams per centimeter cubed (g/cm³) or kilograms

per meter cubed (kg/m³)

molar concentrations

moles per unit volume

units used for molar concentrations

used units are moles per liter or mL, millimoles (mMoles) per liter or mL and nanomoles (nmoles) per micro liter (mL).

molarity (M)

moles of a substance present in 1000 mL (moles/L) of solution (total volume).

unit of concentration of a molecular  species (molecule, ion,etc) in a liter of solution.

how molarity (M) expressed?

expressed in millimoles (mM)

what does solution volume include?

the volume of the solvent and the displacement volume of the solute.

Molarity formula

M = MOL/L = MOL/ 1000mL

What does 1 molar solution mean?

there is 1 mole of a solute in 1 liter of solution.

Normality (N)

equivalents of a substance present in 1 liter (1000 mL) of solution.

Mass in volume ratios

Mass of a dissolved ingredient per volume amount of mixtures containing that ingredient

mEq / per volume

mEq of an electrolyte or salt per unit of volume of solutions containing that electrolyte or salt

Molality (m)

moles (mol)  of a solute/kg of a solvent containing that solute
(1 mol of solute per 1 kg of solvent is a 1 molal (1 m) solution)

Molarity (M)

mol of a solute/L of a solvent containing that solute
(1 mol of solute per 1 L of solution of that solute is a 1 molar (1 M) solution)

Normality (N)

1 Eq of solute per 1 L of solution of that solute is a 1 normal (1 N) solution.

normality formula

Molarity × largest valence ion of a compound)

what normality is?

Equivalents (Eq) of a solute/L of a solvent containing that solute

Parts per million (ppm)

Parts of a gas, liquid, or solid per 1 million part of another gas, liquid, or solid containing the first gas, liquid, or solid

% Volume in volume (% v/v)

mL of liquid per 100 mL of a solvent containing that liquid

% Weight in volume (% w/v)

g of a solute per 100 mL of a solvent containing that solute

% Weight in weight (% w/w)

g of a solute per 100 g of a mixture containing that solute

Ratio strength

1:R

1 part of an ingredient in R parts of a mixture containing that ingredien

1 in R

1 part of an ingredient in R parts of a mixture containing that ingredien

X:Y

X parts of one ingredient per Y parts of another ingredient in a mixture

R, X, and Y are whole numbers

ratio

express concentration as parts of the individual components or part of the components in the total mixture.

same units for numerator and denominator so they cancel out

what the unit part of weight

grams

what the unit part for milliliters

mL

molar ratio

ratio of the number of moles of one component in the reaction with the number of moles of another component in the reaction.

molar fraction

number of moles of a component as a fraction of the total number of moles.

Parts per million (ppm)

number of parts (g) per million parts of the total mixture.

units are mL for liquids or grams for solids.

what is Parts per million (ppm) used for?

generally used to express very low concentrations (e.g impurities such as metal ions).

concentration

express as the mass /units volume

percentage concentration

defined as the quantity of the substance in100 parts of the total quantity of the mixture

how can percentage be expressed?

expressed as % w/v, or % w/w or % v/v.

if density known?

% w/v can be converted to % w/w

solution

homogeneous liquid prepared by dissolving a solute(s) in a solvent(s)

Dissolution

the physical-chemical process where a solute (solid, liquid, or gas) disperses into a solvent to form a homogeneous mixture called a solution

aqueous solution

water is used as the solvent or co-solvents

nonaqueous solution

water immiscible organic solvents are used as solvent(s)

simple solutions

single solute in a solvent

way to remember: it’s single like u (me specfically me) :)

compound solution

more than one solute and /or more than one solvent

true solution

solute molecules completely dissolve in the solvent to give a clear, transparent homogeneous liquid

fact about true solution

cannot be separated via filtration and is able to transmit light.

Colloidal solution

visibly clear, transparent homogeneous liquid.

colloidal solution reflects light (Tyndall effect)

Micellar solution

dispersion of micelles in a solvent (most usually water) using a surfactants

what does micellar solution form

clear or cloudy solution depending on the size of the micelles

saturated solution

• contains maximum amount of solute in specified solvent volume and temperature

• addition of more solute does not increase solubility

unsaturated solution

less than the saturation concentration

Addition of more solute will give clear homogeneous solution

supersaturated solution

• Under certain conditions (pH), the equilibrium solubility exceeds saturation concentration

• Unstable and easily precipitates or crystalizes

stock solution

concentrated solution which must be diluted before use

mix with water or another solvent to make it apporiate concentration

what is Stock solution

the orginal solution

has the higher concentration and needs to be diluted

what happens when diluted

concentration of the final solution is always lower than that of the stock (original) solution.

How dilution expressed?

Solute : Solvent

Dilution Factor

the factor by which the stock solution or an aliquot is diluted.

Solute: Solution

concentration factor

initial volume divided by the final solution volume.

 

solute

solid liquid or gas used to form solution with solvent

solvent

the liquid

what does solublity depend on?

depend on ablity of solute to interact and form bonds with solvent

requirement for solute

sufficent energy to overcome intermolecular forces that keep solvent molecules together

solvation

dissolving

solute molecules can diffuse independently through the solution

saturated

maximum solublity

intrsnic solubilty

max amount of solute to dissolve in specfic volume of solvent (saturationn at specfic temp and pressure)

unsaturated

concentration LESS than intersnic solublity concentration

What happens with insoluble compounds?

unable to assoicate with solvent and form bonds with its molecules (remains immiscble or undissolved in solvent)

Ionic Bonds

metal atom loses electrons to nonmetal

covalent bond

two nonmetals share electrons

Hydrogen bond

Hydron attracts F,O,N

Metallic Bonds

postive metals ions attract conducting electrons

what is mass

measure of the amount of matter in a substance

what is weight

meausre the force of gravity acting on an object

relationship between mass and weight

they are proportional

why is mass and weight proportional

gravitational force on earth is a constant

units

metric units in life sciences is grams (g)

Smaller units used are milligrams (mg), micrograms (the werid looking m g) and nanograms (ng),

Calculate the weight of the syrup

Beaker WITH SYRUP - Beaker WITHOUT

13.668g - 9.144g

Answer: 4.524g

units

used to provide information about measured entity or result of a calculation