10 minutes maximum! (can you do it in 5?) Grab a calculator and Periodic Table - time for some maths! |
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1. The simplest whole number ratio of atoms in a compound is the . | |||||||||||||||||
2. The actual number of atoms in a molecule is the . | |||||||||||||||||
3. The empirical formula of the compound formed when 0.2 mole of metal X combines with 0.4 mole of non-metal Y is ….
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4. The simplest formula for the compound formed when 16g of sulfur reacts completely with 24g of oxygen is …….
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5. The plastic melamine has the empirical formula CH2N2 and a molar mass of 126g/mol. The molecular formula of melamine is:
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Q6-7. Hydrocarbon X has a relative molecular mass of 42 and contains 85.7% carbon and 14.3% hydrogen. 6. The empirical formula of X is:
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7. The molecular formula of X is:
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8. 0.20g of magnesium oxide was formed by heating 0.12g of magnesium ribbon in a crucible.
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Calculate the number of moles of magnesium and oxygen atoms in the magnesium oxide.
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Q9-10. An oxide of copper was reduced to copper by heating in methane gas in the apparatus shown here: The following results were obtained:
[Relative atomic masses: Cu = 64; O = 16] |
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9. The masses of copper and oxygen in the original sample are:
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10. The formula of the oxide of copper is….
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