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easy chemistry Calculations
發問:
1.)Copper reacts with dilute nitric acid according to the equation below. If 2 moles of copper metal are allowed to react with an excess of nitric acid, what is the theoretical yield of NO gas (in grams) that can be formed? Assume the copper is completely consumed. (Round your answer to the nearest tenth of a gram,... 顯示更多 1.)Copper reacts with dilute nitric acid according to the equation below. If 2 moles of copper metal are allowed to react with an excess of nitric acid, what is the theoretical yield of NO gas (in grams) that can be formed? Assume the copper is completely consumed. (Round your answer to the nearest tenth of a gram, or one decimal place). The theoretical yield of NO gas is _______ grams. 3Cu(s) + 8HNO3(aq) ---->3CU(NO3)2(aq) + 2NO(g) +4H2O(l) 2.)You need to make 192.0 g of aluminum oxide according to the equation shown below. How many grams of aluminum metal must you start with? You may assume that all of the aluminum will be consumed in the reaction. (Round your answer to the nearest tenth of a gram, or one decimal place). You will need ____ grams of aluminum metal. 4Al(s)+ 3O2--->2Al2O3 3.)Under the appropriate conditions, you can combine acetic acid and methanol to form methyl acetate and water (see balanced equation below). You attempt this experiment in CHEM 233 using 90.0 grams of acetic acid and 64.0 grams of methanol. You obtain an actual yield of 52.2 grams of methyl acetate. What is your percent yield? (Report your answer to the nearest tenth of a percent, or one decimal place, e.g. XX.X%). Your percent yield is_____%. acetic acid +methanol---->methyl acetate+ water
最佳解答:
1.According to the equation, the theoretical yield of NO gas are 2X2/3 moles when 2 moles Copper is completely consumed. so The theoretical yield of NO gas is 2x2/3x28=37.3grams the answer is 37g 2.192x4x27/102=203.29 the answer is 203g 3.the molecular weight acetic acid 60g.....1.5moles methanol 32g 2moles methyl acetate 74g....52.2/74moles The theoretical yield of methyl acetate are1.5moles 52.2/[74x1.5]x100%=47% The answer is 47 percent
其他解答:
第一提也是錯的,NO分子量是14+16=30.|||||1. From the reaction equation: 3Cu(s) + 8HNO3(aq) ---->3Cu(NO3)2(aq) + 2NO(g) +4H2O(l) 2 moles of copper can generate (2/3 x 2) moles of nitric oxide after copper is fully consumed. Molar mass of NO is 30.006 g/mol Therefore theoretical yield of NO gas is 4/3 x 30.006 = 40.0 g (one decimal place) 2. Molar mass of Al2O3 is 101.96 g/mol; molar mass of Al is 26.98 g/mol 192.0 grams of Al2O3 is equal to 192/101.96 = 1.883 moles From the reaction of oxidizing aluminum, 1.883 moles of Al2O3 requires 1.883/2 x 4 = 3.766 moles of Al Therefore we need 3.766 x 26.98 = 101.6 grams of Al. (one decimal place) 3. Molar mass of acetic acid (CH3COH) is 60.05 g/mol Molar mass of methanol (CH3OH) is 32.04 g/mol Molar mass of methyl acetate (CH3COOCH3) is 74.08 g/mol 90.0 grams of CH3COOH is equal to 1.50 moles. (90/60.05) 64.0 grams of CH3OH is equal to 2.00 moles. (64/32.04) From the esterification reaction, CH3COOH + CH3OH D CH3COOCH3 + H2O we know one molecule of CH3COOH reacts with one molecule of CH3OH, thus 1.5 moles of acetic acid is the limited agent. The theoretical yiled of methyl acetate is 1.5 moles, or 1.5 x 74.08 = 111.12 grams. Now we got 52.2 grams of methyl acetate, thus the percent yield is 52.2/111.12 x 100% = 47.0%. References: http://en.wikipedia.org/wiki/Nitrogen_monoxide http://en.wikipedia.org/wiki/Al2o3 http://en.wikipedia.org/wiki/Aluminium http://en.wikipedia.org/wiki/CH3COOH http://en.wikipedia.org/wiki/CH3OH http://en.wikipedia.org/wiki/Methyl_acetateC8D74AB62542840B
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