Question Bank by Edumentors
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What's the significance of the mole concept when calculating reacting quantities in chemical equations?
The mole concept allows us to count substances in terms of their atoms, molecules or ions, making it easier to balance chemical equations and understand stoichiometry. For example, if a reaction requires 2 moles of hydrogen gas to react with 1 mole of oxygen gas, you can easily calculate the mass or volume of each rea
How does the concept of hybridisation explain the geometry of methane?
In methane, the carbon atom undergoes sp3 hybridisation, forming four equivalent hybrid orbitals. These orbitals arrange themselves in a tetrahedral shape to minimise electron repulsion. This hybridisation explains why all the H-C-H angles in methane are 109.5 degrees and why the molecule is symmetrical.
What role do van der Waals forces play in the properties of noble gases?
Van der Waals forces are the primary intermolecular forces between noble gas atoms. These are weak forces but they increase with the size of the atoms. This explains why the boiling points of noble gases increase down the group, even though these elements are generally non-reactive.
How does the structure of diamond contribute to its hardness?
Diamond has a giant covalent structure where each carbon atom is tetrahedrally bonded to four other carbon atoms. This three-dimensional network of strong covalent bonds makes diamond extremely hard and gives it its unique mechanical properties.
Why does fluorine have a higher electronegativity than iodine, even though they are both halogens?
Fluorine has a higher electronegativity than iodine because it is much smaller and its valence electrons are closer to the nucleus. This allows fluorine to exert a stronger pull on shared electrons in a bond, making it more electronegative. Iodine's valence electrons are further away from the nucleus and experience mo
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