Shared Flashcard Set

Details

CAPE CHEMISTRY 1 STUDY GUIDE F
questions geared at things you may sadly forget when doing CAPE unit 1 Chemistry
33
Chemistry
12th Grade
05/02/2012

Additional Chemistry Flashcards

 


 

Cards

Term
Trend in stability melting of period 3 elements down the group from Na to Si
Definition
Increase down group from Na to Si
Term
Conductivity wise what is Si
Definition
Semi- conductor
Term
Trend in first ionization across period 3 from left to right?
Definition
Increase in 1st IE from left to right
Term
Nature of oxide of Aluminium
Definition
amphoteric
Term
Nature of Magnesium chloride
Definition
weaky acidic (6.5 ish)
Term
Reaction of clorine (VII)oxide in water 
Definition
strong acid of HClO4  forms
Term
Equation of Aluminum oxide with hot, concentrated sodium hydroxide 
Definition
Al2O3(s) + 2NaOH(aq)+ 3H2O(l)---> 2NaAl(OH)4
Term
Reaction of silicon(IV) oxide with  hot and concentrated sodium hydroxide
Definition
SiO2(s)+ NaOH(aq)---> Na2SiO3 (aq) + H2O(l)
Term
What is the nature of sodium chloride?
Definition
neutral - NaCl (aq)
Term
Reactivitiy with water across period from left to right?
Definition

Decrease from left to right of period 3 with water

 

 

HOWEVER

Cl2 reacts with water 

Cl2(g)+ H2O(l)---> HCl (aq)+ HOCl(l)

Term
Reactivity of Group 2 with water
Definition

Reativity increass down group

Be has no rxn with water

 

Ca(s)+ H2O(l) --> Ca(OH)2(aq) +H2(g)

Term
Trend in solubility of hydroxides of Group 2?
Definition
Increase in solubility down group 2 from Be to Ba
Term

Solubility of SULPHATES down the group 2?

 

(PLEASE REMEMBER)

Definition

Decrease in solubility down the group 2.  

 

 

Solubility affected by ndothermic lattice enthalpy and exothermic enthalpy of hydration. The more exothermic the overall rxn then the more soluble the products! Enthalpy of hydration decreases down group 2 while lattice enthalpy relatively constant due to large size of sulphate. 

 

Get it. Set it. Don't Forget it...once group 2 on exam paper...this is more than likely on it!!!!!!!!!!!

Term
What is the trend in thermal stability of group 2 carbonates?
Definition

stability increases down the group

 

 

takes in consideration endo lattice enthalpy and exo enthalpy of formation

 

CaCO3(s)--> CaO(s)+ CO2(g)

Term
Why is the aqueous solution of Na2O more basic than that of MgO? 
Definition

Na2O forms NaOH which is completely soluble in water and thus dissociates completely 

MgO forms Mg(OH)which is barely soluble in water thus does not dissociate as readily to release OHions.

Therefore the former is the stronger base.

Term
Why do transition metals have a stronger melting point than s-block elements?
Definition
First bond is metallic therefore the greater the amount of electrons then the stronger the bond and more difficult it is to break as is the case with transition metals. Secondly transition metals have a smaller atomic radius than s-block element so there is a greater effective nuclear charge on the atoms thus much more difficult to break. 
Term

Why is BaSO4 acceptable when X-ray analysis  though Ba2+ ions are toxic? 

 

 

CAPE question of 2007

Definition
BaSO4 used as it is solid and allows for the Xray of the colon as Xray cannot bypass it. BaSO4 is INSOLUBLE in water thus no Ba 2+ ions will form. 
Term
Uses of CaCO3
Definition

treating drinking water

shell of lobster 

Term
Trend in ionization energy down group 4?
Definition

Ionization energy decreases down the group 

 

because IE inversely proportion to atomic radii which in this group increases down the group.

Term
Nature of the oxides of Sn in both +2 and +4 oxidation state
Definition
amphoteric
Term
Acid/base Nature of CO
Definition
neutral
Term

Explain relative stability  of oxides of group 4 elements of oxidation states +2 and +4.

 

 

 

CAPE question 2003  worth 4 marks :P

Definition

Relative stability of +4 oxidation state decreases down group and thus +2 increases down the group as highlighted clearly with Pb which is most stable as PbO.

 

Take in consideration the thermal decomposition of the group 4 dioxides...all stable EXCEPT PbO2 which decomposes to give PbO

Term

Reaction of lead (IV) oxide with sodium hydroxide

 

 

Is the reaction similiar for Sn?

Definition

PbO2 (s)+ 2NaOH(aq)--> Na2PbO3 (aq) + H2O(l)

 

 

Yep real similiar

Na2SiO3(aq) only difference in product

 

 

Term

Reaction of lead (IV) oxide with  a concentrated acid (like HCl)

 

 

clue (similiar rxn of Sn)

Definition
PbO2(s) + 4HCl(aq)--> PbCl4(l) + H2O (l)
Term
Reaction of SnO with NaOH 
Definition

SnO(s)+ NaOH(aq)+ H2O(l)--> NaSn(OH)3 (s)

 

H2O of the NaOH solution reacts with SnO 

Term
Trend in boiling point of tetrachlorides of group 4
Definition
increases down group EXCEPT CCl4  which is high and PbCl4 which decomposes (as usual, its in a stable relationship with +2 so you know the thing)
Term
Overall reaction of SiCl4(l) with water.
Definition

SiCl4(l)+ 2H2O(l)--> Si(OH)4+ 4HCl(aq)

 

but then Si(OH)4--> SiO2(s)+ H2O(l)

 

Thus:

SiCl4(l)+ 2H2O(l)--> SiO2(s)+ 4 HCl(aq)

Term

Account for this: When exposed to the atmospher, SiCl4 produces white fumes while no such fumes are produced with CCl4?

 

CAPE question 2010 

 that  part of the question worth 5 marks in total.

Definition

SiCl4 is hydrolysed to silicon (IV) oxide and HCl gas with the water in the atmosphere due to presence of vact d sub shell...the fumes seen is a mixture of the white precipitate of the oxide and the colourless fumes.

 

C of CCl4 has no d subshell much les a vacant one and thus a lone pair of the oxygen of water could not form a dative covalent bond with it and hydrolysis would and could NOT occur.  

Term
Trend in hydrolysis of group 4 elements down the group?
Definition

Decrease in ease of hydrolysis down the group as metallic character increases. 

 

CCl4 does not take part in hydrolysis due to absence of empy d orbitals.

Term
Give proof of atomic shells
Definition
Sucessive ionization energies of an atom  such as Na... the large increases in ionization enerrgies at points indicate  electron closer to nucleus than predecessor  thus must be in a inner shell...Tada!
Term
What effect does decreasing the temperature of a endothermic reaction do to the equilibrium position?
Definition
Decreasing temperature causes reaction to favour the exothermic reaction to replace energy lost thus equilibrium position shifted to the left!
Term

It has been observed that a solution of aqueous chromium (III) ions, [Cr(H2O)6]3+ (aq) is weakly acidic. Suggest an explanation for this observation?

 

CAPE question 2006

Marks 2

 

Definition

First and foremost...all cations of transition metals in complexes are Lewis acids as they attact lone pairs  from their ligands.

 

Secondly, all 3+ oxidation state aqua transition ions are more acidic than 2+ due to their high charge density in comparison to others.

Term
Basis on which transition metals act as homogenous catalysts
Definition

Variable oxidation state

 

This allows them to act as intermediates in reactions.

Supporting users have an ad free experience!