What does this question mean 15, what does this question mean

Wrong question, is it H2S and SO2, it should not be water and SO2 analysis: ABromine water has strong oxidizing properties, H2S and SO2 are reducible, and can undergo redox reactions with bromine water.

b.Acidic KMNO4 is explained in the same way as A.

c.Concentrated HNO3 Ibid.

Solution H2S + CuSO4 = Cus (precipitation) + H2SO4 This reaction is a typical reaction of weak acid to strong acid, and SO2 does not react with CuSO4.

H2S and SO2 gas bar.

Both gases are oxidized to S and SO4(2-) in ABC, respectively

Only H2S in D reacts to produce Cus (acid-insoluble precipitate).

The meaning of the question is: H2O and SO2 only react with which of the following solutions?

The answer is DBecause the SO2 and CUSO4 solutions react. And H2O and it doesn't react.

d, the title is wrong, cus is a precipitation, and there can be no reaction between s+6 and +4, nor can it produce precipitation.

The answer is that both the sulfur in DA hydrogen sulfide and sulfur dioxide can be oxidized by bromine water.

b Ibid. c Ibid.

dOnly hydrogen sulfide can be neutralized with copper sulfate.

4-valent sulfur cannot react with 6-valent sulfur.

This question is to test you about several valencies of sulfur.

ABC can be seen to be wrong on visual inspection (not explained here).In the d option, only H2S reacts to produce Cus

A and B are multiplied by x 2-4 = (x + 2) (x-2), B and C are multiplied by x 2 + 15x-34 = (x - 2) (x + 17), and the tour group is (x + 2), B is slow grinding (x-2), and C is (x + 17).

Due to the disturbance, the sum of A and C is 2x+19.

Assuming the number is ab, its reverse is ba.

The condition is, (10a+b)-(10b+a) = 5(a+b), find ab+ba.

According to the conditions, 9a-9b = 5a+5b, 4a=14b, 2a=7b, so a=7, b=2

The number is 72, its reverse is 27, and the sum of them is 99

With water as a reference (assuming the water is stationary), the direction of movement of the lifeguard.

Relative to water, which is to think of water as a static lifeguard movement.

Hopefully, thank you.

a<0，|a|=-a

b<0，|b|=-b

a|<|b|

a<-b

Both sides of the inequality are divided by -1, and the direction of the inequality sign changes.

a>b

a<0 and b<0, then both a and b are negative.

a|<|b|, the absolute value of a negative number is its opposite.

a<-b

a>b

Directly brought in, assuming that the absolute value of a = 1 and the absolute value of b is 2, then a = -1 and b = -2That's it. Don't think about it so complicated, just bring in the simplest algorithm.

Please send the full **, you can't see the whole.

Set up a workshop x person competition.

92x+87*（80-x）=80*90

92x+87*80-87x=80*90

5x=240

x=48 So, 48 people went to the first workshop, and 32 people went to the second workshop.