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WorksheetsOCR Chemistry A – 'Polarity and IMFs' (2.2.2k-m)
Total questions: 12
Worksheet time: 24mins
S=C=S has the same shape as CO2.
TICK ALL TRUE STATEMENTS:
CS2 is totally symmetrical i.e. the two dipoles cancel out.
CS2 is polar
permanent dipole-dipole forces are the strongest intermolecular force in CS2
The C–S double bond is polar
TICK IF MOLECULE IS POLAR
CCl4
CH3CH3
PBr3
TICK CORRECT STATEMENTS
at room temperature and pressure, some covalent compounds are solids, some are liquids, and some are gases
covalent bonds exist between molecules
in covalent bonds, electrons are transferred between atoms
SiO2 contains covalent bonds
In CH3CH2OH(s), which intermolecular force is the strongest?
ionic bonding
London forces
permanent dipole-dipole forces
hydrogen bonding
For which group of chemicals are permanent dipole-dipole forces the strongest intermolecular force for ALL compounds?
CO2, CS2, CSe2
CH3Cl, NO, HF
CH2Cl2, CO, PBr3
H2O, H2Se, H2S
Which is the best explanation for H2O having a higher melting point than H2S
"The hydrogen bonds in H2O are stronger and take more energy to break."
"The hydrogen bonds in H2O are stronger than the permanent dipole-dipole forces in H2S. Hydrogen bonding takes more energy to break."
"Hydrogen bonding in water is stronger than the London forces in H2S"
"The H2O molecules are held in an open lattice"
O=C=O has a lower boiling point than S=C=S.
Which is the best explanation?
CS2 has more electrons and stronger London forces
CS2 has more electrons and the bonds between molecules are stronger than in CO2
the C=O bond is more polar than the C=S bond, because O is more electronegative than S
CO2 only has London forces, whereas CS2 has permanent dipole-dipole forces
Here are some standard explanations that you might use.
SELECT ANY THAT ARE NOT GOOD.
hydrogen bonds are hold apart water molecules in an open lattice, so the solid substance is less dense
the molecule is totally symmetrical, so the bond dipoles cancel.
the bonds between molecules are broken when boiling
ionic bonds are much stronger than intermolecular forces so need more energy to overcome
Which of the series of steps is the correct recipe to judge the strongest intermolecular force in a substance?
1) does the molecule contain O, F, or N atoms? 2) is the molecule polar?
1) does the molecule contain an O–H, N–H, F–H bond? 2) does the molecule contain lone pairs?
1) does the molecule contain OH, NH, FH 2) is the molecule polar?
1) does the molecule contain an O–H, N–H, F–H bond? 2) is the molecule polar?
TICK ALL CORRECT STATEMENTS:
If the substance has hydrogen bonding...
the melting and boiling points will be anomalously high
the molecule must contain an O–H bond
it must also have London forces
it must also have permanent dipole-dipole forces
What is the missing feature of this diagram?
What are the labels (1) & (2)?
(1) covalent bond (2) hydrogen bond – missing: dipoles
(1) hydrogen bond (2) hydrogen bond – missing: dipoles
(1) hydrogen bond (2) covalent bond – missing: lone pairs
(1) hydrogen bond (2) covalent bond – missing: dipoles
Which substance has permanent dipole-dipole forces?
CH3–O–CH3
CH3–O–CH2CH3
CH3CH2–O–CH2CH3
CH3CH2CH2CH2–O–CH2CH2CH2CH3
