1. 23.4 g of sodium chloride (NaCl) solid was dissolved in 2.0 dm3 of solution. What is the molarity of the solution?
2. What mass of solute is present in 500.0 cm3 of 0.10 M sodium hydrogencarbonate solution?
3. 9.98 g of copper(II) sulphate crystals CuSO4.‧5H2O are used to prepare a 0.500 M solution. What is the volume of solution formed?
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F4 Chem concentration of soln
2013-03-27 4:22 am
回答 (1)
2013-03-27 8:45 am
✔ 最佳答案
1.Molar mass of NaCl = 23 + 35.5 = 58.5 g/mol
No. of moles of NaCl = 23.4/58.5 = 0.4 mol
Molarity of the solution = 0.4/2.0 = 0.2 M
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2.
No. of moles of NaHCO3 = 0.1 x (500.0/1000) = 0.05 mol
Molar mass of NaHCO3 = 23 + 1 + 12 + 16x3 = 84 g/mol
Mass of NaHCO3 = 84 x 0.05 = 4.2 g
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3.
Molar mass of CuSO4•5H2O = 63.5 + 32 + 16x9 + 1x10 = 249.5g/mol
No. of moles of CuSO4•5H2O = 9.98/249.5 = 0.04 mol
Volume of the solution = 0.04/0.500 = 0.08 dm³ = 80 cm³
參考: 胡雪
收錄日期: 2021-05-01 13:06:35
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