Miscellaneous Flashcards
What must always be included when writing formulae of IONS responsible for MOLECULAR ION peaks or fragment peaks
- a positive charge
-if the molecule wasn’t charged it wouldn’t be detected in the mass spectrometer
Ideal gas equation and units of each component
pV = nRT
p = pressure in pascals (Pa)
V = volume (m^3)
n= number of moles
R = gas constant (8.31 J mol^-1 K^-1)
T = temperature (Kelvin)
What is the danger of metal oxides
They are corrosive
Use of bumping granules
Provides a surface for bubbles to form on
Factors affecting Rf values
- different adsorption to stationary phase (chromatography paper)
-different solubility in the mobile phase
(Solvent)
What is the rate equation for Sn1 reactions
Rate = k [ tertiary halogenoalkane]
- as the slowest (rate-determining step) is the heterolytic fission of the R-X bond forming the carbocation intermediate
What is the rate equation for Sn1 reactions
• Rate = k [ tertiary carbocation]
• As slowest (rate-determining) step in Sn1, is homolytic fission of R-X bond to form carbocation intermediate
What is the rate equation for Sn1 reactions
• Rate = k [ tertiary halogenoalkane]
• As the slowest (rate-determining) step in Sn1 is homolytic fission of R-X bond to form carbocation intermediate
How can you make an reaction E cell reaction that isn’t feasible at standard conditions feasible?
-change the conditions
-so that you decrease or increase the standard electrode potential of one of your species
-so E cell is no longer negative
What is the rate equation for Sn2 reactions
- Rate = k [ primary halogenoalkane][nucleophile]
-As the slowest (rate-determining) step in Sn2 is the attack of the nucleophile on the halogenoalkane
Why are transition metalaqua ion complexes acidic in solution
-the small positively charged central metal cation polarises an O-H bond
-making it easier for water ligands to release hydrogen ions into solution
-metal aqua ions release protons in solution
Weak acid-strong base titration pH @ equivalent point
- pH >7
- @ equivalence point A- from ,weak acid ,HA react with water, releasing OH- ions into solution, making the pH at the equivalence point slightly basic
Strong acid-weak base titration pH @ equivalence point
-pH <7
-@ equivalence point salt made is slightly acidic (has a weak acidic), which partially dissociates at the equivalence point
What is region formed during the titration of a strong acid and a weak base
-Buffer Region
-When [HA] = [A-] , acting as reservoirs, neutralising added base
Why is standard enthalpy of Neutralisation for a weak acid less eco thermos than that or a strong acid
- weak acids do not fully ionise
-therefore more energy has to be put in /used to fully ionisie the acid
What is a reagent
A substance or compound added to a system to cause a chemical reaction or test if one occurs
What allows for electrons to be promoted within quantum shells e.g sulfur can promote electrons from the 3s and 3p subshell to the 3d subshell
- all of these sub shells are in the same quantum energy level (n=3)
-therefore the difference in energy between the sushells isn’t HUGE, so not too much energy needs to be put in to promote the electrons
(As you move lower down in the periodic table octet expansion becomes rarer as gaps within subshells get larger as you move down quantum shells)
What is a the pro to expanding an octet for an atom, despite it taking Energy to promote the electrons
- they can form more covalent bonds
-covalent bond formation is exothermic, therefore the more bonds you form, the form energy you release
-so the atom is more stable
