Calculating Molar Mass Grade 9a
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What is the molar mass of Carbon?
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6 g/mol
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12.01 g/mol
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19.00 g/mol
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1.01 g/mol
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This quiz titled 'Calculating Molar Mass grade 9A' assesses knowledge on molar masses of various compounds including Carbon, Methane, Ammonium Carbonate, and more. It enhances understanding of molecular weights essential for chemistry students.
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- 2.
What is the molar mass of CH4 (methane)?
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12.01 g/mol
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13.02 g/mol
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16.05 g/mol
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32.10 g/mol
Correct Answer
A. 16.05 g/molExplanation
The molar mass of a substance is determined by the average atomic mass according to the periodic table. There is 1 carbon in CH4 (methane) and 4 hydrogen:
Carbon 1 (12.01) + Hydrogen 4(1.01) = 16.05 g/molRate this question:
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- 3.
What is the molecular mass of Cu3(PO4)2?
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253.49 g/mol
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380.59 g/mol
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110.22 g/mol
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348.59 g/mol
Correct Answer
A. 380.59 g/molExplanation
Molar mass is the mass of ONE mole of a substance regardless of how many moles there are in the equation. CAUTION: The parentheses indicates that everything within the parentheses is MULTIPLIED by the subscript outside of the parentheses.
This means there are 3 Coppers, 2 Phosphorus, 8 oxygen:
Copper 3 (63.55) + Phosphorus 2(30.97) + 8 (16.00) = 380.59 g/molRate this question:
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- 4.
What is the molar mass of (NH4)2CO3 (Ammonium carbonate)?
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96.11 g/mol
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82.10 g/mol
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106.11 g/mol
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43.01 g/mol
Correct Answer
A. 96.11 g/molExplanation
Molar mass is the mass of one mole of the substance. The molar mass of a substance is determined by the average atomic mass according to the periodic table. CAUTION: The parentheses indicates that everything within the parentheses is MULTIPLIED by the subscript outside of the parentheses. This means there are 2 nitrogen, 8 hydrogen (4 x 2), 1 carbon and 3 oxygen in this compound.
Nitrogen 2(14.01) + Hydrogen 8 (1.01) + Carbon 1 (12.01) + Oxygen 3(16.00) = 96.11 g/molRate this question:
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- 5.
What is the molecular mass of Aluminum nitrate Al(NO3)3 from this equation: 2Al(s) + 3Fe(NO3)2(aq) à 3Fe(s) + 2Al(NO3)3(aq)
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213.01 g/mol
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335.98 g/mol
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56.99 g/mol
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141.01 g/mol
Correct Answer
A. 213.01 g/molExplanation
(s) means solid and (aq) means aqueous.
Molar mass is the mass of ONE mole of a substance regardless of how many moles there are in the equation. So, ignore the “2” in front of Al(NO3)3
CAUTION: The parentheses indicates that everything within the parentheses is MULTIPLIED by the subscript outside of the parentheses.
This means there is 1 Aluminum, 3 Nitrogen, 9 oxygen (3 x 3)
The molar mass of a substance is determined by the average atomic mass according to the periodic table.
Aluminum 1 (26.98) + Nitrogen 3 (14.01) + Oxygen 9 (16.00) = 213.01 g/molRate this question:
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Current Version
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Mar 17, 2023Quiz Edited by
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Feb 10, 2015Quiz Created by
Mohammad Sayaheen