英语化学题,急（回答出里面任何一题都可以）

英语化学题,急（回答出里面任何一题都可以）
1.How many moles of nitrogen,N,are in 90.0 g of nitrous oxide,N2O?
2.How many moles of methane are produced when 48.1 moles of carbon dioxide gas react with excess hydrogen gas?
3.How many moles of hydrogen gas would be needed to react with excess carbon dioxide to produce 42.1 moles of water vapor?
4.he compound MgSO4 is called Epsom salts.How many grams will you need to prepare a bath containing 5.00 moles of Epsom salts?
5.In a bottle of soda,there is 0.20 mole CO2.How many grams of CO2 are in the bottle?
6.How many moles of O2 are required to react with 6.0 moles H2?
7.If you have 3.0 moles O2,how many moles of H2 are needed for the reaction?
8.How many moles of H2O form when 5.5 moles O2 reacts?
9.What is the molarity of a solution containing 16.8g of KCl in 314 mL of solution?
10.How many liters of a 5.0% （m/v） glucose solution would you need to obtain 95g of glucose?
第一题，Learning Goal:To convert between mass and number of moles.
The conversion factor between mass and number of moles is called molar mass.By consulting the periodic table ,we can determine that the molar mass of NaCl is
23.g/mole+35.g/mole=58.g/mole
This number tells us that 1 \rm mole of NaCl has a mass of 58.5 g .The conversion factors are
58.g/1~mole} and frac{1~mole}{58.g}
Here is an example of the conversion of 12.0 \ moles of \ NaCl to grams using the first conversion factor:
\rm 12.\cancel{\rm moles}\times\frac{58.g}{1~\cancel{\rm mole}}=702~g

1.molar mass of N2O = 2(14)+16 = 44g/mol
So in 90g of N2O there are 90/44 = 2.05mol N2O
Since you want the # mol of nitrogen,there are 2 moles of nitrogen in each mole of N2O
So # mol of N = 2(2.05) = 4.09 (4.10 would be a rounding error)
2.Reaction between CO2 and H2:
CO2 + 2H2 -> CH4 + O2
Since the mol:mol ratio of CO2 and CH4 is 1:1,48.1mol of CH4 will be produced.
3 - 逻辑和第二题一样
4.
Molar mass of MgSO4 = 24.305 + 32.06 + 4(16) = 120.365g/mol
=> Mass of 5mol MgSO4 = 5(120.365) = 601.8g
5.Mass of 1mol CO2 = 12 + 2(16) = 42g
Mass of 0.20 mol CO2 = (0.2)(42)=8.4g
6.Reaction between O2 and H2:
2H2 + O2 -> 2H2O
Mol:mol ratio is 2:1,so for 6 mol H2 you will need 6/2 = 3 mol O2
7.See above - answer is 6.
8.Mol:mol ratio between O2 and H2O is 1:2,so # of moles of H2O formed is 2(5.5) = 11mol
9.Molarity = mol/litre
molar mass of KCl = 39.1+35.45=74.55g/mol
# mol of KCl present = 16.8/74.55 = 0.225mol
314ml = 0.314L
Molarity = 0.225mol/0.314L = 0.718M
10.5% solution means there are 5g of glucose every 100ml.
So for 95g,you will need (95/5)*100 = 19*100 = 1900ml = 1.9L of solution