Chemistry - Reacting Masses

用戶79989

2010-03-01 9:21 pm

please show steps also....

1. Calculate the no. of moles of ions in 60g of CH3COOH.
2. Calculate the no. of moles of ions in 210g of NaHCO3.
3. Calculate the no. of moles of atoms in 30g of C2H6.
4. Calculate the no. of moles of atoms in 10g of SO3.
5. Calculate the no. of moles of ions in 100g of Fe(NO3)3.
6. Calculate the no. of ions in 100g of Na2SO4.
7. If the mass of 1 O2 molecules is y, what is the mass of SO2 molecule in terms of y?
8. If 100g of methane contains X molecules of CH4, how many molecules are there in 300g of propane C3H8 in terms of X?
9. If XO contains 42.86% by mass of X, what is the % by mass of X in XO2?
10. The hydroxide of metal X, X(OH)2, decomposes on heating to give XO and water. If the hydroxide on heating decreases in mass by 24.3% what is the relative atomic mass of X?
11. What is the maxium mass of HNO3 that can be manufactured from 10^5 kg of NH3? Assuming 1 NH3 at most give 1 HNO3 and the % yield of HNO3 os 60%.
THX SOOOO MUCH!!

回答 (1)

micatkie

2010-03-01 10:35 pm

✔ 最佳答案

1.
CH3COOH is a molecular compound containing no ions.
No. of moles of ions = 0 mol

2.
Molar mass of NaHCO3 = 84 g/mol
No. of moles of ions = (210/84) * 2 = 5 mol

3.
Molar mass of C2H6 = 30 g/mol
No. of moles of atoms = (30/30) * 6 = 6 mol

4.
Molar mass of SO3 = 80 g/mol
No. of moles of atoms = (10/80) * 4 = 0.5 mol

5.
Molar mass of Fe(NO3)3 = 242 g/mol
No. of moles of ions = (100/242) * 4 = 1.65 mol

6.
Molar mass of Na2SO4 = 142 g/mol
No. of moles of ions = (100/142) * 3 = 2.11 mol

7.
Molar mass of O2 = 32 g/mol
Molar mass of SO2 = 64 g/mol
Mass of SO2 = y * (64/32) = 2y

8.
Molar mass of CH4 = 16 g/mol
Molar mass of C3H8 = 44 g/mol
No. of moles of CH4 = 100/16 mol
No. of moles of C3H8 = 300/44 mol
No. of C3H8 molecules = X * (300/44)/(100/16) = 1.09X

9.
Molar mass of O = 16 g/mol
Molar mass of X = 16 * 42.86/(100 - 42.86) = 12 g/mol
Molar mass of XO2 = 44 g/mol
% by mass of X in XO2 = (12/44) * 100% = 27.27%

10.
Let y be the relative atomic mass of X.
Molar mass of X(OH)2 = (y + 34) g/mol
Molar mass of XO = (y + 16) g/mol

[(y + 16)/(y + 34)] * 100% = 1 - 24.3%
y = 40
Relative atomic mass of X = 40

11.
Molar mass of NH3 = 17g/mol
Molar mass of HNO3 = 63 g/mol
Maximum mass of HNO3 = 10^5 * (63/17) * 60% = 2.22 * 10^5 kg

2010-03-03 14:30:03 補充：
I am sorry that :
3. should be "No. of moles of atoms = (30/30) * 8 = 8 mol"

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