Unit 4 Glossary Flashcards
Define accuracy
A measure of the agreement between a measurement and the true or correct value
Define actual yield
The quantity of a product that is obtained from a chemical reaction
Define anomalous data
Data with unexpected values that do not match the relationship observed in previous measurements
Define atom economy
A ratio of the total mass of atoms in the desired product to the total mass of atoms in the reactants
What is a back titration
A titration pre-formed when an insoluble and so reacting reagent is treated with an excess of an acid or base
Define chromatography
Attend technique for analysing or separating mixtures of gases liquids or dissolved substances based on differential solubility in two phases
What is a colorimeter
An instrument used to measure the intensity of colour in a solution
Define concentration
The ratio of amount of a substance dissolves in a given volume of solution
What is a dependent variable
The variable that is measured during an investigation
What is emission spectroscopy
The study of emission spectra produced by excited substances
What is gravimetric analysis
A method of quantitive analysis for finding the Composition and formula of compound is based on an accurate weighing of reactants and products
What is an independent variable
The variable that is manipulated or change during an investigation
Define literature value
A value from the chemical literature or a physical constant or experimental measurement
What is a mobile phase
Liquid or gas which personally through or along stationary phase during chromatography
Define percentage error
And Erin expressed as a percentage of the value measured or the true value
Define percentage uncertainty
Random uncertainty/actual measurement times 100
Define percentage yield
The actual yield as a percentage of the theoretical yield
Define precision
The total amount of random error present in a measurement indicates how close together a series of measurements are
Define qualitative analysis
Analysis used to identify the substance but not the quantity of the substance
Define quantitative analysis
Analysis used to determine the quantity of each component of the material or substance
What is a redox reaction
Reaction involving reduction or oxidation which results in one or more electrons being transferred and is accompanied by changes in oxidation numbers
What is a redox titration
A titration used to determine the concentration of a solution of an oxidising or reducing agent
Define retention time
The time between injection of a substance into a chromatography column and the appearance of the peak
What is a separating funnel
Fun over the top at the lower end of the stopper in the tool used to separate immiscible liquids
What is solvent extraction
A method for separating a compound from a mixture by causing it to move to another solvent
What is a standard solution
A solution his concentration is actually known and which does not change with time
What is the stationary phase
One of the two faces forming a crow much to graphic system which may be solid jail or liquid
What is steam distillation
A technique used to purify organic substances that are immiscible with water and which would decomposed if distilled
Define systematic error
An error which bias is your measurements in some predictable way
What is theoretical yield
The maximum amount of mass of a particular product that can be formed when the limiting reactant is completely consumed and there is no losses or side
Define titration
A chemical technique in which one solution is used to analyse another solution and find its concentration or amount
What is vacuum filtration
A mixture of solid and liquid is poor through a filter paper in Büchner funnel the solid is trapped by the filter and the liquid is drawn through the funnel into the flask bellow by a vacuum
Define water of crystallisation
Water molecules contained in the crystal lattice of organic salts when Play crystallise from aqueos solution
