It s a bit of a complicated problem, don t get into it if you re not a high school chemistry master

Remember the special case: fe3 + i - fe2 + i2

mno4-+i-->i2+mn2-

If you think about the existence of these 2 reactions, it's OK.

Support the upstairs, this is not complicated.

Ha ha! This

I do not know!

1 i- is easily oxidized while Fe3+, Fe3+ has strong oxidizing properties, so it cannot coexist Ferrous ions have no effect.

2 The principle is the same as the first question: Mn has reached the most ** non-reaction and there is no intermediate valence non-reaction with ferrous ions.

3 Ferrous ions have reducing properties and are oxidized into three iron ions, so there must be no mno4-

4 Reducible ions cannot be present, i.e. Fe2+ and I-

This topic only needs to understand the reducing and oxidizing properties It is worth noting.

Why do ferrous ions and iron ions one oxidize and the other is reducible and do not react, because redox causes a change in valency, and they have no intermediate valence, so they do not react.

Ferrous ions are also oxidizing, i.e., they are reduced to iron Why is it the same as i-

It doesn't react, because if you react, you will produce i2, and i2 is more oxidizing than ferrous ions, so it can't react.

Fe3+ and Mno4- are oxidizing, Fe2+; i- Reducible.

So that all the problems are solved.

Hehe, like this. The n in ammonia is -3 valent, make a mistake! In hypochlorous acid, Cl is +1 valence O is -2 valence, 2HCCl = 2HCl + O2, 2 Cl atoms gain 4 electrons, 2 oxygen atoms lose 4 electrons, equilibrium.

1.Ethanol is mixed with acetic acid, and the method of removing impurities: add sufficient concentrated sulfuric acid and distill.

What's wrong? (Ethanol and acetic acid will react under the action of concentrated sulfuric acid to form ethyl acetate) The correct way is not to add quicklime and distill (right CaO+2CH3COOH=Ca(CH3CoO)2+H2O)).

2.About nitrates: a

It's all strong oxidants, why is it right? (What I remember is that nitrate is a strong oxidant at high temperatures, and nitrates can release oxygen at high temperatures, because oxygen is a strong oxidant at high temperatures, so all those that can release oxygen at high temperatures are strong oxidants.) ）

b.They are all colorless crystals, no, please give counterexamples (Cu(No3)2, Fe(No3)2, Fe(No3)3).

3.The equation for the reaction of calcium carbide with water, what type of reaction device should be? (CAC2 + 2H2O CH three CH Ca(OH)2 solid-liquid at room temperature).

4.Concentrated nitric acid and copper sheets are prepared with a solid-liquid device at room temperature to prepare NO2, and the gas washing cylinder of concentrated sulfuric acid is used to wash the gas, and it is collected by the upward exhaust air method, where is the fault (yes, NO2 is a harmful and toxic gas, and it cannot be allowed to enter the air, so the upward air exhaust method cannot be used, the air exhaust method should be used, and you can refer to the air exhaust method to define that an exhaust gas treatment device should be added when collecting NO2. ）

Oxygen to 2ozone is an exothermic reaction, why is it wrong? (It should be an endothermic reaction, ozone has a relatively strong oxidizing capacity, you can think of it as ozone has a large energy, and oxygen has a small energy.) From small to large, of course, it has to be heated.

Ozone usually breaks down into oxygen and releases heat. No conditions are required, and the typical high energy wants low energy conversion. If both positive and negative are heat-emitting, wouldn't there be a perpetual motion machine? ）

Acetic acid is volatile, directly add concentrated sulfuric acid to the mixture to heat, acetic acid will overflow with ethanol, and the mixture is still obtained. Quicklime and acetic acid are added to react to produce acetate, the boiling point is increased, and then distilled to obtain purer ethanol.

2。The nitrogen element in nitrate is positive pentavalent, which has strong oxidizing properties, not to mention in solution. Nitrate is explosive, mainly because of its oxidizing nature. The color of nitrates is also related to cations, such as copper nitrate.

3. CAC2+2H2O=Ca(OH)2+C2H2 device is solid-liquid room temperature 4. The mistake lies in the collection method, which is the upward exhaust air method.

5。It is an endothermic reaction.

1. Ethanol reacts with concentrated sulfuric acid under heating conditions, 2, I don't understand 3Cac2+2H2O=Ca(OH)2+acetylene, redox reaction, 4, density, this air is large, 5 endothermy.

Esterification occurs under the action of concentrated sulfuric acid; Failure to add quicklime will produce salts with a high boiling point.

The landlord should be asking about the amount and concentration of the substance.

m(h2so4) =50 * 98% *=n(h2so4) = =

c(h2so4) = =

SO2 is a gas, oxygen is another gas, of course it does not contain oxygen B, water in nature will dissolve a small amount of oxygen in the air (oxygen can be dissolved in water) C should be needless to say, the air contains oxygen.

Liquid oxygen in d is liquid oxygen, which of course gets oxygen after evaporation, just like water evaporates to get water vapor.

The answer is a

Oxygen is dissolved in water in nature.

There is oxygen in the air to breathe.

Oxygen gas is formed after the evaporation of liquid oxygen.

It should be A, there is dissolved oxygen in the water, there is oxygen in the air, and the liquid oxygen is oxygen after evaporation!

It's a bWater in nature is not pure, it is dissolved in oxygenWherever there is air, there will be oxygen.

d.The gas obtained by the evaporation of liquid oxygen is, of course, oxygen, (oxygen has a lower boiling point than nitrogen) aSulfur dioxide is SO2 is this substance, compound.

SO2 is pure, what does the fish in the water suck, liquefied oxygen vapor is still oxygen, and the air is a mixture that cannot be pure.

Not included! Matter is made up of molecules or atoms, and molecules are made up of atoms or ions.

Let the volume of the mixed solution be v

It is known by the conservation of k+ v=

The amount of substance to which H2SO4 is added:

Set the volume v1 to which concentrated sulfuric acid is added

v1×v1=

If H+ is used to calculate the volume of concentrated sulfuric acid.

The amount of substance to which H2SO4 is added:

It's a bit problematic to use SO42- to calculate, your data is wrong.

The amount of sulfate in the original solution is the concentration of the substance.

Concentrated sulfuric acid VL is added

v＋v≈

Volume multiplied by density multiplied by mass fraction divided by relative molecular mass is equal to two times the concentration of hydrogen ions.