Chemistry - Ans.fyi 參考答案

Chemistry

2012-02-19 12:53 am

Stoichiometry and Yields of a Decomposition Reaction
Ammonium dichromate decomposes according to the following reaction.(NH4)2Cr2O7
圖片參考：https://lewis.chem.sfu.ca/res/sfu/batchelo/Gallery/rarrow.gif
N2 + 4H2O + Cr2O3
What mass of H2O can be formed from the decomposition of 91.9 g of (NH4)2Cr2O7?

What mass of Cr2O3 can be formed from the decomposition of 91.9 g of (NH4)2Cr2O7?

What mass of N2 can be formed from the decomposition of 91.9 g of (NH4)2Cr2O7?

回答 (1)

sioieng

2012-02-19 5:27 am

✔ 最佳答案

(NH4)2Cr2O7→ N2+ 4H2O + Cr2O3

Formula mass of (NH4)2Cr2O7 = 14x2+ 1x8 + 52x2 + 16x7 = 252
No. of moles of (NH4)2Cr2O7 =91.9/252 = 0.3647 mol

No. of moles of H2O formed = 0.3647 x 4 = 1.459 mol
Formula mass of H2O = 1x2 + 16 = 18
Mass of H2O formed = 1.459 x 18 = 26.3 g

No. of moles of N2 formed = 0.3647 mol
Formula mass of N2 = 14x2 = 28
Mass of N2 formed = 0.3647 x 28 = 10.2 g

No. of moles of Cr2O3 formed = 0.3647 mol
Formula mass of Cr2O3 = 52x2 + 16x3 = 152
Mass of Cr2O3 formed = 0.3647 x 152 = 55.4 g

參考: sioieng6

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