paper 1 Flashcards
Give the full electron configuration of an Al atom and a Cr3+ ion (2)
1) Al= 1s2 2s2 2p6 3s2 3p1
2) Cr3+ ion= 1s2 2s2 2p6 3s2 3p6 3d3
Deduce the formula of the compound that contains 2+ ions and 3- ions that both have same electron configuration as Argon (1)
Ca3P2
Deduce which of Na+ and Mg2+ is the smaller ion. Explain your answer (2)
1)Mg2+
2) Because Mg2+ has more protons with the same shielding
Write an equation to represent the process that occurs when the first ionisation energy of sodium is measured (1)
Na(g)—->Na+(g) + e-
Explain why the first ionisation energy of sulfur is different from that of phosphorus (2)
1)e− paired in 3p orbital in Sulfur
2) Paired e− repel so less energy needed to remove electron
Name the type of bond formed between N and Al in H3NAlCl3 and explain how this bond is formed (2)
1) co-ordinate bond
2) Shared pair of / both electrons come from the N(H3
In terms of structure and bonding, explain why the boiling point of bromine is different from magnessium and suggesy why magnessium is a liquid over much greater temperature range compared to bromine (5)
STRUCTURES
1) bromine is simple molecular
2) magnesium is metallic
STRENGTH
3) bromine has weak van der waals forces between the molecules
4) so more energy is needed to overcome the strong metallic bonds.
LQUID RANGE
5) Mg has much greater liquid range because forces of attraction in metal are stronger.
Explain how ions are accelerated,detected and have their abundance determined in a TOF mass spectrometer (3)
1)Ions accelerated by attraction to negatively charged plate
2)Ions detected by gaining electrons
3)Abundance determined by size of current flowing or amount of electrons gained in the detector
Student identified use of burette as largest source of uncertainty in the experiment. using same apparatus, suggest how procedure could be improved to reduce percentage uncertainty in using burette (2)
1) suggestion= use larger mass of solid
2) justification= so a larger titre will be needed
Student is required to make upto 250cm3 of aqueous solution that contains known mass of MHCO3. Student is provided with sample bottle containing the MHCO3. describe the method,including appratus and practical details,that student should use to prepare solution (6)
STAGE 1 - transfer known mass of solid (2 marks)
-weigh sample bottle containing solid on a 2 d.p. balance
-transfer to beaker and reweigh sample bottle
- record difference in mass
STAGE 2- dissolve in water (2 marks)
-add distilled water
-stir with glass rod until all solid dissolved
STAGE 3- transfer,washing and agitation ( 2 marks)
- transfer to volumetric flask with washings and make up to 250cm3
-shake/mix
Write the full electron configuration for Cl- and Fe2+ (2)
1)Cl− 1s2 2s2 2p6 3s2 3p6
2) Fe2+ 1s2 2s2 2p6 3s2 3p6 3d6
Write an equation, including state symbols, to represent the process that occurs
when the third ionisation energy of manganese is measured (1)
1) Mn2+ (g) → Mn3+ (g) + e−
State which of the elements magnesium and aluminium has the lower
first ionisation energy.
Explain your answer. (3)
1) Al
2)Outer electron in 3p orbital
3) Higher in energy/further from the nucleus
so easier to remove
Give the meaning of the term electronegativity (1)
Power of an atom to attract a pair of electrons in a covalent bond.
Explain how permanent dipole-dipole forces arise between hydrogen chloride
molecules (2)
1) Difference in electronegativity leads to bond polarity
2) and there is an attraction between ∂+ on one molecule and ∂- on
another
Name the shape of SiH4
Tetrahedral
Name the shape of BeCl2
Linear
Balance the equation ……CuFeS2 + ..…O2 + ..…SiO2 → ..…Cu2S + ..…Cu2O + ..…SO2 + ..…FeSiO3
4CuFeS2 + 9.5O2 + 4SiO2 → Cu2S + Cu2O + 7SO2 + 4FeSiO3
Balance the equation …….Cu2S + ……Cu2O → ……Cu + ……SO2
Cu2S + 2Cu2O → 6Cu + SO2
Suggest two reasons why the sulfur dioxide by-product of the process is removed
from the exhaust gases.
1) Prevents acid rain-which damages buidlings
2) Toxic
State two differences between the ‘plum pudding’ model and the model of atomic
structure used today (2)
1) nucleus now contains protons and neutrons
2)Electrons are now arranged in orbitals
deduce the full electron configuration of Nitrogen (1)
1s2 2s2 2p3
Explain how ions are detected and relative abundance is measured in a TOF mass
spectrometer (2)
1) ion hits the negative plate and gains an electron
2)relative abundance is proportional to the size of the current