paper 1 practise Flashcards
(26 cards)
how to calculate no. of atoms/electrons removed
mass/mr x 6.02x10^23
what anomalies are there in transition elements?
Cr/Cu as they both have 4s^1
Explain why the boiling point of PH3 is lower than the boiling point of NH3 (both in group 5)
- NH3 has hydrogen bonding (FON)
- H bonding is a much stronger imf
explain why the boiling point of PH3 is lower than the boiling point of AsH3 (both in group 5)
- As has more electrons than P
- in AsH3 stronger induced dipole-dipole interactions
what is the systematic name for KClO4?
potassium chlorate (VII)
^G diagram what parts of the graph indicate what?
P/y-axis=enthalpy change/delta H
gradient= - delta S
link to y=mx+c
where Q/y intercept at (x-axis temperature) crosses is where the reaction becomes feasible
suggest apparatus that would allow gas volume to be collected
using a 1dm^3 gas syringe
suggest a different experimental method that would allow the rate of this reaction to be followed over time
measure mass loss
how to calculate rate constant
rate/[a][b]
general idea of equilibrium and temperature
endo direction=increase temperature to get it in the endo direction
exo direction=decrease temperature to get it in the exo direction
why may operational conditions used by the chemical industry be different?
low temp/pressure=slow rate
high temperature=large amount of energy/fuel needed and used
general rules in Kc units
more top than bottom=mol+ dm-
more bottom than top=dm first and + then mol -
when the student prepares the buffer solution, the volume of solution increases slightly, what is the effect on the pH?
stays the same as the ratio/proportion of [HA]/[A-] is the same
define average bond enthalpy
breaking one mol of bonds in gaseous molecules
how to calculate Ea from lnk 1/T graph
-gradient x 8.314 (R)
how to calculate pre-exponential factor, A
A=e^lnA
chemist increases the pressure of the equilibrium mixture at the same temperature state/explain in terms of Kp how you’d expect the equilibrium position to change
- eqm shifts to RHS
- ratio in Kp decreases
- ratio then increases to restore Kp
describe and explain how the student should determine the end point of this titration accurately (when S2O3)
add starch near end point as it goes from blue to colourless
electron configuration rules transition elements
put 3d first then if able to remain partially filled add 4s
link between equilibria and electrode potentials
more negative E=shifts to LHS
more positive E=shifts to RHS
define weighted mean mass
the average mass taking into account the relative abundancies of the isotopes
what gives the numerical value of the avogadro constant? (1 marker on multiple choice)
number of electrons lost by 20.05g of calcium when it reacts with oxygen
20cm3 of 0.10 moldm-3 HCl is added to 10cm3 of 0.10 moldm-3 NaOH what is the pH of the resulting mixture (how would you calculate this?)
- excess mol HCl =0.1/0.1=1 mol
- excess mol/final volume=1/30=0.03
- square root 0.03 to get 0.173
- then do pH calculation -log to get 0.73 and x by 2 to get a pH of 1.48
what is the key part in calculating the no. of ions via avogadros constant
to x moles by how many ions there are e.g.MgBr2=3 ions therefore you times mol by 3
