F4 CHEM reacting masses

1.
Molar mass of (NH4)2CO3 = 2x(14 + 1x4) + 12 +16x3 = 96 g/mol
No. of moles of (NH4)2CO3 = 9.6/96 = 0.1 mol

1 mole of (NH4)2CO3 contains 2 moles of NH4⁺ ions.
No. of moles of NH4⁺ ions = 0.1 x 2 = 0.2 mol


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2.
1 mole of (NH4)2CO3 contains 1 mole of CO3²⁻ ions.
No. of moles of CO3²⁻ ions = 0.1 mol


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3.
1 mole of (NH4)2CO3 contains 8 moles of Hatoms.
No. of moles of H atoms = 0.1 x 8 = 0.8 mol


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4.
No. of H atoms = 0.8 x (6.02 x 10²³) = 4.816 x 10²³

2012-12-15 00:40:31 補充：
L = Avogadro's number

No. of molecules in 2 g of O2 = [2/(16*2)] * L = L/16 = x
L = 16x

No. of molecules of 14 g of N2 = [14/(14*2)] * L = (1/2) * 16x = 8x ...... (answer)

2012-12-15 00:41:17 補充：
「補充」是補充問題的不足，而不是用來增加題目。