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fe + s = fes (1)
The sum of the equations Fes + H2S04 = FeS04 + H2S (2)(1)(2) gives Fe + S + H2S04 = FeS04 + H2S
The amount of the substance emitting the gas is 3 8mol, and if the emitted gas is only H2S, the mass of the mixture should be 33g instead of 29g. Then rewind back and push, the condition holds, so FE is excessive.
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If you look at the equation carefully, a molecule of iron reacts to form a molecule of gas (hydrogen or hydrogen sulfide), so the amount of iron can be determined based on the total amount of gas.
In fact, it can be understood that iron and acid react to form hydrogen, and part of hydrogen reacts with sulfur to form hydrogen sulfide. In this way, the amount of gas produced is only related to the amount of iron, and the amount of iron can be calculated according to the amount of gas generated, and then the amount of sulfur can be calculated, and then the amount of iron produced can be compared to determine whether there is too much iron.
Think about it yourself.
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The appearance of the third proves that the feg is overdosed.
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ch3CHO+O2====CH3COOHCH3CHh+H2====CH3CH2O2CH3CH2CH2OH+O2==Cu AG==2CH3CH2CH2CHo+2H2O2CH3OH+O2==AG CU==2CH2O+2H2O2CH3OH+2NA====2CH3ONA==H2CH2=CH2+H2O== (certain conditions)==ch3ch2ohch3cooh+ch3oh==(concentrated H2SO4, heated, reversible)==CH3cooch3+H2och3cooh+ch3ch2CH2OH== (concentrated H2SO4, heated, reversible)==CH3cooch2ch2ch3+H2och3cooh+ch3-choh-ch3==(concentrated H2SO4, heated, reversible)==CH3cooch(CH3)CH3+H2OCH2OOH+CH3OH==(concentrated H2SO4, heated, reversible)==CH2OOCH3+H2OOH+CH3CH2OH==(concentrated H2SO4, heated, reversible)==CH2OOCH2CH3+H2OOH+CH3CHHCH3==(concentrated H2SO4, heated, reversible)==CH2OOCH(CH3)CH3+H2OCH3CH2COOH+CH3OH==( Concentrated H2SO4, heated, reversible) ==CH3CH2COOCH3+H2OC3CH2COOH+CH3CH2OH==(Concentrated H2SO4, heated, reversible)==CH3CH2COOCH2CH3+H2OC3COOH+CH3CH2CH2OH==(Concentrated H2SO4, heated, reversible)==CH3COOCH2CH2CH3+H2OH (Is your teacher sick, this kind of question) o-o-h||ch3o2;h-c-h;ch2oohhho-o-h|||ch3h6o2;h-c-c-c-hch3ch2cooh||hhch3ch2cooch2ch2ch3+h2o==(alkaline conditions, heating)==ch3ch2cooh+ch3ch2ch2oh(c6h5)-cooch2ch3==(alkaline conditions, heating)==(c6h5)-cooh+ch3ch2oh tired old man, if it weren't for my good mood, I wouldn't write to you ==
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The nitrification reaction of glycerol also needs to be heated.
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1.Due to the different dropping sequences, the phenomena are different:
HCl and Na2CO3
HCl is added to Na2CO3: HCl + Na2CO3 = NaHCO3 + NaCl without gas.
Na2CO3 is added to HCl: 2HCl+Na2CO3=2NaCl+CO2+H2O drops into the gas immediately.
ALCL3 and NaOH
AlCl3 is added to NaOH: Al3++4OH-=ALO2-+2H20 without precipitate.
3alo2-+al3++6h2o=4al(oh)3 and then there is a precipitate.
NaOH is added to AlCl3: AlCl3 + 3NaOH = Al(OH)3 + 3NaCl has a precipitate to form.
Al(OH)3 + NaOH = Naalo2 + 2H2O precipitate dissolves.
HCL and Naalo2
HCl is added to Naalo2: H++ALO2-+H20=AL(0H)3 Existing precipitate Continue to add HCl and the precipitate disappears.
Naalo2 is added to HCl: ALO2-+4H+=Al3++2H20
agNO3 and NH3·H2O
AgNO3 drops are added to ammonia to generate a white precipitate agoh
The addition of ammonia to AGNO3 is a phenomenon in the silver mirror reaction, and the existing precipitation disappears after excess.
2. The phenomenon is different depending on the amount of dropping
na2co3+hcl=nahco3+nacl
na2co3+2hcl=co2+2nacl+h2o
Carbon dioxide passes into the clarified lime water, and there is a white precipitate (calcium carbonate) first, and when the carbon dioxide is excessive, the solution becomes clear again, and the product is calcium bicarbonate.
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Ca2+ +2HCO3- +2OH- =CaCO3 +CO3(2-) 2H2O
co2 + clo- +h2o ==hco3- +hclo
cl2 + 2oh- =cl- +clo- +h2o
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Mn in KMno4 decreases from +7 to +2, and S rises from -2 to 0 in H2S, and the number of gained and lost electrons is equal.
So the coefficient kmno4:h2s=2:5
The other coefficients are then trimmed. Pick D
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The answer is that the price of two mns in D is reduced by a total of 10, so there should be five sulfurs oxidized.
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d, the gains and losses of electrons should be conserved
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d is chosen because the gain and loss electrons are not conserved.
1) cyclohexane + Cl2 --- light ---monochlorocyclohexane + HCl2) monochlorocyclohexane + NaOH ---ethanol, heated --- cycloethylene + NaCl + H2O >>>More
fe+s=△=fes
2so2o2 >>>More
agno3+nacl=agcl()+nano3 ag+ +cl+=agcl
bacl2+na2so4=baso4+2naclcuso4+na2s=cus+naso4 >>>More
1. For those relatively simple chemical equations for balancing, the best way to use is the least common multiple methodFor example: mg+o2 ignition = mgo, the number of oxygen atoms on the left is 2, and the number of oxygen atoms on the right is 1, then the least common multiple of 2 and 1 is 2, then the coefficient in front of the magnesium oxide on the right should be 2, the coefficient in front of the magnesium oxide has become 2, then the coefficient in front of the magnesium atom should also be 2, the final formula should be 2mg+o2=2mgo, of course, the final must indicate the conditions for the chemical reaction, For example, magnesium reacts with oxygen to form magnesium oxide, and the condition required is to ignite oxygen, and finally the correct chemical formula can be obtained: 2mg+O2 ignition ==2mgo >>>More
hcl+agno3=agcl+hno3
nacl+agno3=nano3+agcl2mgcl+2agno3=mg(no3)2+agclh2so4+bacl2=2hcl+baso4h2so4+ba(no3)2=2hno3+baso4na2so4+bacl2=2nacl+baso4k2so4+ba(oh)2=2koh+baso4h2so4+ba(oh)2=baso4+2h2omgso4+ba(oh)2=mg(oh)2+baso4cuso4+ba(oh)2=cu(oh)2+baso4na2co3+2hcl=na2co3+h2o+co2na2co3+h2so4=na2so4+h2o+co2k2co3+2hno3=2kno3+h2o+co2caco3+2hcl=cacl2+h2o+co2caco3+2hno3=ca(no3)2+h2o+co2mgco3+2hcl=mgcl2+h2o+co2co2+2naoh=na2co3+h2o >>>More