Copper(II) Sulfate forms a bright blue hydrate with the formula CuSO4 ·n H2O(s). If this hydrate is heated to?
2017-04-26 10:38 am
Copper(II) Sulfate forms a bright blue hydrate with the formula CuSO4 ·n H2O(s). If this hydrate is heated to a high enough temperature, H2O(g) can be driven off, leaving the off white anhydrous salt CuSO4(s). A 4.020-g sample of the hydrate was heated to 300 °C. The resulting CuSO4(s) had a mass of 2.542 g. Calculate the value of n in CuSO4 ·n H2O(s).
回答 (2)
2017-04-26 10:52 am
Molar mass of CuSO₄ = (63.5 + 32.1 + 16.0×4) g/mol = 159.6 g/mol
Molar mass of H₂O = (1.0×2 + 16.0) g/mol = 18.0 g/mol
Mass of CuSO₄•nH₂O = 4.020 g
Mass of CuSO₄ = 2.542 g
Mass of H₂O = (4.020 - 2.542) g = 1.478 g
Mole ratio CuSO₄ : H₂O
= (2.542/159.6) : (1.478/18.0)
= 0.0159 : 0.0821
= (0.0159/0.0159) : (0.0821/0.0159)
= 1 : 5.16
≈ 1 : 5
Hence, n = 5
Molar mass of H₂O = (1.0×2 + 16.0) g/mol = 18.0 g/mol
Mass of CuSO₄•nH₂O = 4.020 g
Mass of CuSO₄ = 2.542 g
Mass of H₂O = (4.020 - 2.542) g = 1.478 g
Mole ratio CuSO₄ : H₂O
= (2.542/159.6) : (1.478/18.0)
= 0.0159 : 0.0821
= (0.0159/0.0159) : (0.0821/0.0159)
= 1 : 5.16
≈ 1 : 5
Hence, n = 5
2017-04-26 10:38 am
Idk
收錄日期: 2021-04-18 16:10:11
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https://hk.answers.yahoo.com/question/index?qid=20170426023830AAzSfE3