SS1 Chemistry 3rd Term Exam 2023/2024

Chemistry SS1 3rd Term Examination

Gases and Gas Laws

• P1V1 = P2V2 supports Boyle's law
• The unit of n in the ideal gas equation PV = nRT is moles (c)
• The phenomenon where atmospheric pressure equals saturated vapour pressure is called normal pressure (d)

Acids and Bases

• The presence of sodium chloride in ice lowers the freezing point of sodium chloride (d)
• The escape of molecules with more than average kinetic energy is called evaporation (c)
• Ethanoic acid C2H4O2 has a basicity of 1 (b)

Bonds and Compounds

• The types of bonds in H3O+ are covalent and coordinate covalent (b)
• The oxidation number of sulphur in H2SO4 is 6 (d)
• Trioxonitrate (V) acid is written as HNO3 (b)

Chemical Reactions

• The major reason chemical reactions occur among elements is that they have a tendency to attain the nearest noble gas structure (a)

Electrovalency and Crystal Structure

• In electrovalency, most metallic atoms with few valence electrons give out electrons because they are unstable (a)
• The arrangement of ions in a regular pattern in a solid crystal is called a lattice (c)
• If force is applied to an electrovalent crystal, the shape and crystal structure may be deformed (d)

Atomic Structure and Molecules

• Atomicity of ozone is 3 (c)
• A molecule is the smallest particle of a substance that can exist in a free state (a)
• The electronic configuration of an element X with atomic number 9 and mass number 19 is 2,7 (a)

Chemical Bonding

• The bond type in a diatomic nitrogen gas is a triple covalent bond (b)
• The bond type between copper(II) ion and water molecules is a dative covalent bond (d)
• The bond between two iodine molecules is a van der Waal's force (d)

Inter molecular Forces

• Bonds between a highly electronegative atom and a hydrogen from another molecule are called hydrogen bonds (a)
• Rare gases are stable because they have duplet or octet electronic configurations in the outermost shells of their atoms (d)
• Isotopes of an element have the same atomic number (d)