What is the difference between molecules and compounds?
Compound are substances with two or more different kinds of elements bonded together. Water is a compound made of elements hydrogen and oxygen. Table sugar is a compound made of elements carbon, hydrogen, and oxygen.
Some compounds are made up of molecules, such as table sugar, known as sucrose. The molecular formula for sucrose is C12H22O11. This is read as 12 atoms of carbon, 22 atoms of hydrogen, 11 atoms of oxygen.
The molecular formula for sucrose tell how many atoms of each kind of element makes up one molecule, but does not tell how the atoms are bonded together.
Structural and skeletal formulas do give information about how the elements are bonded together. Compounds made up of molecules have covalent bonds (bonds in which the atoms share electrons). Each single covalent bond is indicated by a single line in structural and skeletal formulas. Each covalent bond represents the sharing of two electrons between the connected atoms.
Count the number of carbon, hydrogen, and oxygen atoms in each of the formulas. Do they add up to the molecular formula for sucrose, which is C12H22,O11?
FYI: Each carbon atom should have 4 connecting bonds. You will find this true in the structural formula, but the skeletal formula only shows what is connected to the rings. You are suppose to know that carbons have 4 connecting covalent bonds. Compare the two formulas to see where carbon and hydrogen atoms are left off in the skeletal formula.
The structural formula for sucrose is:
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