A chemistry genius in high school and a physics genius

Solution: Let the chemical formula of the metal be r, its valency is x, and its molecular mass is m, then its chemical equation is: 2r+xcl2=2rclx, and the molecular weight of the > solid is 71x

71x/71=2*m/50

m=25x, when x=1, the molecular formula weight of the two metals should be greater than 25 and the other should be less than 25, when x=2, the molecular formula weight of the two metals should be greater than 50 and the other should be less than 50, when x=3, the molecular formula weight of the two metals should be greater than 75 and the other should be less than 75, because m(na)=23, m(potassium)=39, so it meets the first requirement, so choose c

Suppose the metal is x and the valency is +1

2x+cl2=2xcl2m 71

So m=25

If the metal is +2, the atomic weight is 2, +3, +4 ......Similarly.

So the molar mass of the two metals must be greater than 25 and less than 25al: 27 3=9 <25 fe:56 3<25mg:

24/2=12<25 zn:65/2>25 cu:64/2=32>25

So choose C

a.Let the unary test quantity of the two metals be m, and their corresponding substances be e, then.

2e+cl2=2ecl2 ^m

2m :71 : 71-2m

50g : 71g

That is, 50*(71-2m)=2m*71

The solution m= means that one of the two metals must be greater than the unary test quantity of one metal, and the unary test quantity of one metal is less than the answer. al=27/3=9

fe=56/2=28

mg=24/2=12

na=23/1=23

k=39/1=39

zn=65/2=

cu=64/2=32

Therefore, I chose A but I am the first in chemistry in my grade, believe me 0 )

2x+cl2=2xcl

50/(21/71mol*2)

This is the average molecular weight.

After being converted into a price.

Aluminum is 27*3=81

Iron is 56*3=168

Magnesium is 24*2=48

So choose A

Dissolve the same volume of nitric oxide and nitrogen dioxide mixed gas in water, NO2 reacts with water, 3NO2 + H2O = 2HNO3 + NO, it can be seen that 3 volumes of NO2 become 1 volume of NO, and the volume is reduced by 2 volumes, so the remaining gas is NO, and the volume is 3 + 1 = 4, which is the original 4 6 = 2 3.

Let each have 3 volumes, and the total volume is 6

After the reaction, 3 volumes of NO2 become 1 volume of NO, and the original NO remains unchanged.

So the remainder is (3+1) 6

The centripetal force when sliding over the bottom of the bowl is fn=mv 2 r=n-mg, so n=m(g+v 2 r), so the frictional force f=un=um(g+v 2 r), so b

I wanted to say it, but I was robbed

The one on top.

According to the redox reaction in the valence of the total number of reductions to equalize, it is known that the sulfur before the reaction is +6 valence, the element is 0, and the sulfur after the reaction is +4 valence, then the total price reduction is (6-2)a, if the element is non-metallic, after the reaction shows x valence, then the price rise is x = 2 a, if the element is metal, then the x valence is shown after the reaction, but it should be noted that there are x 2 moles of sulfuric acid has not been reduced, and it is acidic, according to the total number of valency reductions in the redox reaction, it is equal to (6-2) (a-x 2) = x, and the solution is x=a

What is SO4 gas It should be SO2 Do you make a mistake? o is -2 valence, s is not +8 valence.

If it is SO2, M---H2SO4 (concentrated) 1---A

For example, Cu+H2SO4 (concentrated) is a partial valence chemical valence rise and fall balance: m increases x valence * 1 = s decreases 2 valence * a 2 (because s element is partially valence).

x=a, e.g. c+h2so4 (concentrated).

The chemical valence is up and down: m increases x valence * 1 = s decreases 2 valence * a (s element all valence).

x=2a

The highest valency of S is +6 valence of SO4 is not possible.

Elemental + H2SO4= SO2 + something.

1 : S in AH2SO4 is +6 valence and becomes SO2 +4 valence after reflection It means that the S in H2SO4 is reduced to 2 valence and the amount of the substance that needs it is a So.

Elemental + H2SO4= SO2 + something.

1 ： ay 2*a

So y=2a

Elemental + H2SO4 = SO2 + Something + SO41 : A

y'A so y'=a

The emitted gas should be SO2.

Hello! Two solutions:

x=2na+2h20=2naoh+h2

x y zy=80x/46

z=2x/46

Mass fraction of solute = m solute m solution.

Now solute = (100*

Now solution = 100+x-2 46x

Mass fraction of solute = [(100*

x=Hope you can add some more points, thanks!

Because Lao Bai has a cowardly side in his personality, coupled with his weak communication skills, he is not famous, although he is a partner in the Nobel Prize project.

The quality of C is required to be macro and quantitative, and the quality of D is first sought out.

m=n*m requires a pure absolute vertical d mass to be larger, you need to know n and m, and you can find n if you know the gas volume under the standard condition

Finally, according to the conservation of mass, the mass of c can be found.

m(c)=m(a)+m(b)-m(d)