Chem Textbook

Question 1

Electrons have a specific amount of energy when occupying a subshell. What are energy levels?

Answer 1

Energy levels are the energies of electrons in subshells in an atom.

Question 2

How do the electrons of atoms transition to higher energy levels

Answer 2

Through the absorption of energy.

Question 3

What happens through the emission of energy

Answer 3

electrons transition to lower energy levels `

Question 4

how do the electrons transition between energy levels in atoms

Answer 4

through the absorption and emission of energy in the form of photons of electromagnetic radiation

Question 5

is the wavelength of electromagnetic radiation absorbed and emitted by an element unique.

Answer 5

yes

Question 6

How does AAS work?

Answer 6

a cathode lamp of the specific metal emits specific wavelengths of electromagnetic radiation that are absorbed by the electrons in the atoms of the element in the atom of the element under analysis. a quantity of radiation is absorbed if the element is present in the sample.

Question 7

What is absorbance

Answer 7

the quantity of light absorbed by the sample

Question 8

Why are other elements not affected in the measurement of a specific element

Answer 8

the presence of other elements in the sample does not affect the measurement of the concentration of the element under analysis as other elements do not absorb the specific wavelength of electromagnetic radiation emitted by the specific element.

Question 9

what is a standard solution

Answer 9

a solution of accurately known concentration

Question 10

what is a primary standard

Answer 10

when a standard solution is made form a solid;

the solid should be highly pure, not react with air, be soluble in water.

Question 11

what is back titration

Answer 11

a back titration involves reacting a material with a known quantity of a reagent. the quantity of reagent added is always more than required to react completely. the number of moles of the reagent in excess form the reaction with the material of interest is then determined by titration. calculations are then performed to determine the number of moles of the material of interest that reacted with the reagent.

Question 12

analyte

Answer 12

the component or substance being analysed

Question 13

titrant

Answer 13

the substance of known concentration (usually liquid) added to the analyte in a titration

Question 14

titrate

Answer 14

the solution being titrated in order to determine its concentration

Question 15

titre

Answer 15

the total volume of solution delivered by the burette to reach the endpoint of the titration

Question 16

equivalence point

Answer 16

the point at which complete chemical reaction takes place and the point when the mole ratio of the titrant and the analyte are chemically equal to their reaction equation.

Question 17

endpoint

Answer 17

the point just past the equivalence point where there is a sudden change in a physical property, such as indicator colour change, pH, conductivity or absorbance