High School Chemistry Multiple Choice, Xie High School Chemistry Multiple Choice. Ask the great god

A is clearly wrong.

If it is ground into a fine powder, then the pyrite is in full contact with himself, how can the oxygen be "intimate" with him, it is all powder, the oxygen can't get in, it is still lumpy, and the gap between the iron ore and the iron ore is large, so the contact with oxygen is also large.

b is a bit tangled, and I think it should affect the ...... of the rateHa, after all, n years of studying chemistry.

Multiple selections? The cd is definitely right.

After thinking about it, I felt that B was right, because it reacted with the air.

It's solid, so it should have an effect on the pressure.

ps For those who mislead people's children and other people's problems, you have to be responsible, don't make yourself very nb, a is obviously wrong, and I don't know whose brain is in water.

It should be the choice of baThe increased contact area increases the reaction rate.

b.Increasing the pressure is equivalent to increasing the concentration, which can increase the reaction rate. So b is not right.

c.Increasing the temperature can increase the reaction rate, and for every 10 degrees of temperature increase, the reaction rate increases by 2 4 times.

d.The separation of the product is equivalent to increasing the concentration of reactants and increasing the reaction rate.

It's all in this book, so take a good look! In the chapter "Chemical Equilibrium". I'm taking the college entrance examination this year! Miserable!

B false. Because the reactant has 11 mor O2, the product has only 8 mor so2The volume varies. The change in pressure must affect the rate of the chemical reaction.

Item a. Grinding into powder is beneficial to increase the contact area with O2. Burn fully.

Item c. As the temperature increases, the molecular movement accelerates. There is a high chance of breaching. Quick response.

Item d. Chemical equilibrium moves.

Choose B to see clearly, he said that he chose the wrong one!

The first floor is really smart.,It's actually said that a is obviously wrong.,The brain is in water.。。

Option B, 11 oxygen to produce 8 carbon dioxide, positive reaction decompression, negative reaction pressurization, so the pressure can change the reaction rate.

bPlease: The topic should also be level!

W, Y, and Z are short-period elements with different periods and different main groups, indicating that there is an element that is H, according to the diagram structure, W forms +2 valence cations, X forms 2 covalent bonds, Y can form 4 single bonds, and Z forms 1 covalent bond, then Z is an H element, W is in group A, and X is in group A; If the electron configuration outside the simple ion nucleus corresponding to W and X is the same, W is Mg, and X is the O element. The sum of the outermost electrons of w, y, and z is equal to the number of outermost electrons of x, and the outermost electrons of y is 6-2-1=3, and y is in the group a. It can be concluded that it is mgb2o8h4, so b

b is correct, whether it is white phosphorus or red phosphorus combustion, it is an exothermic reaction, so δH1 and δH2 are less than 0.

The conversion of 1mol of white phosphorus into 1mol of red phosphorus is based on the conservation of phosphorus atoms, so the following thermochemical reaction equation is actually to use white phosphorus and red phosphorus containing the same amount of phosphorus atoms to burn, so it can be understood in this way: white phosphorus is converted into red phosphorus and releases heat, indicating that "the energy of white phosphorus containing phosphorus atoms of the same amount of substance is higher than that of red phosphorus", and red phosphorus is more stable than white phosphorus. According to the conservation of energy, when burning, white phosphorus emits more heat than red phosphorus, then δH1 <δH2

a.Mistake. This is because the adapted strip hood is a standard gas (atmospheric pressure, 0 °). At room temperature and pressure, the molar volume of the gas is not equal to.

b.Mistake. 1 ammonia molecule contains 4 atoms. So 1mol of ammonia should contain 4mol of atoms, then according to n=n na. Contains atomic number 4Na.

c.That's right. 32g of oxygen is 1mol, and 1 oxygen molecule contains 16 electrons, so the number of electrons contained in 1mol of oxygen is 16na

d.Mistake. You can use the limit method, assuming that 28g is all co, or co2 to calculate stupidly, you can get the answer you want.

a correct, at room temperature and pressure, compared with the standard condition, the pressure is the same, the temperature increases, so the molar volume of the gas increases, then the amount of the gas should be less than.

b False, the atomic number of 1mol NH3 should be 4Na

c Correct, 32g oxygen is 1mol, 1 oxygen atom contains 8 electrons, then 1 oxygen molecule is 16, 1mol is 16mol, so the number of electrons is 16na

d False, this question can only be assumed by the limit assumption, 28g of CO is 1mol, 28g of CO2 is about , so the number of molecules can only be between 1Na.

Based on the information you provide, there is certainly not only one answer to this question. You turn your mind shut up and see if you have copied the question incorrectly.

Ca, the crystal with anions must contain cations --- attack, and the anions must be ionic crystals, so there must be cations.

This question can also be asked the other way around, there must be anions in the crystals with cations, which is wrong, because the crystals with cations can be ionic crystals or metal crystals, and there are no anions in the latter.

b. Metal is a good conductor of electricity and heat--- which is the universal property of metal Li Feng.

c. The melting point of metal crystals is higher than that of molecular crystals--- which is wrong, such as Hg is liquid at room temperature, but molecular crystal I2 is solid at room temperature.

d. The substance that can conduct electricity in the solid state is not necessarily a metal --- pair, the most typical is graphite.

d.I have done this question, and my class teacher has specially emphasized that D is the standard answer.

The explanation is that it is absolutely impossible for the influenza virus to damage the immune system, and at the current level of human development, only a virus like AIDS can damage the immune system, and the influenza virus is impossible because the cells it infects will not damage the immune system.

ABC is all right, all of them are good to explain that the virus mutation causes antigen changes, and the primary antibody does not work; Another flu virus is also well understood: antibodies can also disappear quickly, leading to illness.

Select D, 65% nitric acid solution has acidity and strong oxidation, the test paper first turns red and then is oxidized and bleached to white, 98% of the sulfuric acid is acidic, strong oxidation, and dehydration, so the test paper is finally dehydrated and turned black, and the hypochlorous acid in the new chlorine water has strong oxidation, so the test paper is finally oxidized and bleached into white.

Select d concentrated sulfuric acid to turn black, dehydrated and carbonized.

Concentrated nitric acid and newly made chlorine water first turn red, then white, strong oxidation.

Option D first nitric acid is strongly oxidizing, starting to acidify the litmus to turn red, and then oxidizing the litmus to make it white.

The second sulfuric acid has strong dehydration, which can make the binding water of the test strip be removed, carbonized, and turn black.

Thirdly, chlorine water, like nitric acid, is oxidized. turn white.