paper 1 chemistry Flashcards
In terms of electrostatic forces, suggest why the electron affinity of fluorine has a
negative value.
There is an attraction between the nucleus and
electron(s)
Energy is released (when the electron is gained)
Define the term enthalpy of hydration of an ion.
Enthalpy change when 1 mol of a gaseous ion
forms aqueous ions
Explain why magnesium has a higher melting point than sodium.
Mg2+ / magnesium ion has higher charge than Na
+Attracts delocalised / free / sea of electrons more strongly / metal–
metalbonding stronger / metallic bonding stronger
State the structure of, and bonding in, silicon dioxide.
Other than a high melting point, give two physical properties of silicon dioxide that are
characteristic of its structure and bonding.
Macromolecular
Covalent / giant covalent
properies , hard , brittle insoluble non conductor
Give the formula of the species in a sample of solid phosphorus(V) oxide.
State the structure of, and describe fully the bonding in, this oxide.
P4O10
Structure: Molecular
Bonding: Covalent / shared electron pair van der Waals’ / dipole–dipole forces between molecules
Sulfur(IV) oxide reacts with water to form a solution containing ions.
Write an equation for this reaction.
SO2 + H2O → H+ + HSO3–
Write an equation for the reaction between the acidic oxide, phosphorus(V) oxide, and
the basic oxide, magnesium oxide.
P4O10 + 6MgO → 2Mg3(PO4)2
[Cu(H2O)6]2+ (aq) forms with a reagent to form a pale blue ppt , whats the reagant and the equation for it .
NaOH
[Cu(H2O)6]2+ + 2OH– → [Cu(H2O)4(OH)2] + 2H2O
[Cu(H2O)4(OH)2] reacts with a reagent to form deep blue solution . whats the reagant and equation for it
conc Nh3
[Cu(H2O)4(OH)2] + 4NH3 → [Cu(H2O)2(NH3)4]2+ + 2H2O + 2OH–
[Cu(H2O)6]2+ reacts with a reagent and forms a green blue ppt , whats the reagent and equation
Na2CO3
OR [Cu(H2O)6]
2+ + Na2CO3 → CuCO3 + 6H2O + 2Na+
[Cu(H2O)6]2+ reacts with a reagent to form a yellow green solution , whats the reagent and equation
HCl or NaCL
[Cu(H2O)6]2+ + 4Cl– → [CuCl4]2– + 6H2O
Deduce half-equations for the electrode reactions in a hydrogen–oxygen fuel cell.
H2 → 2H+ + 2e–
O2 + 4H+ + 4e–→ 2H2O
Explain why a fuel cell does not need to be recharged.
Hydrogen / the fuel / reactants supplied continuously / fed in
Write an equation to show how the [Co(NH3)6]2+(aq) ion reacts with 1,2-diaminoethane. Explain the thermodynamic reasons why this reaction occurs.
[Co(NH3)6]2+ + 3NH2CH2CH2NH2→ [Co(NH2CH2CH2NH2)3]2+ + 6NH3
increase in number of particles
entropy increases
∆H is approx. zero
∆G is negative
Write an equation for the reaction of propanoic acid with sodium carbonate.
2CH3CH2COOH + Na2CO3 2CH3CH2COONa + H2O + CO2
The pH of the pH 9.00 solution changed more than that of the other solution.
Suggest what substance might be present in the air to cause the pH to change.
Explain how and why the pH of the pH 9.00 solution changes.
CO2pH (It) falls/decreases CO2 + OH–HCO3–
State and explain how you could distinguish between the two enantiomers.
plane polarised light rotates opposite directions
Give a reagent that could be used in a test-tube reaction to distinguish between
benzene and cyclohexene.
Describe what you would see when the reagent is added to each compound and the
test tube is shaken.
bromine
benzene nvc
cyclohexene discolourised
