A certain class of students is in practice, and a certain class of students is doing the production

hcl+fe

HCL+FEO is not possible

Because the pH value is 1, it means that the solution is strongly acidic, and metals, metal oxides, alkalis, strong acids and weak alkali salts cannot exist in the acidic solution.

The equation is. Fe + 2HCl = FeCl2 (ferrous chloride) + H2Fe2O3 + 6HCI = = = 2Feci3 + 3H2ONoOH + HCl = H2O + Nac

na2co3+2hcl=2nacl+h2o+co2↑

It is impossible to have it in the waste liquid.

fe+2h+==fe2+ h2↑

fe2o3+6h+==2fe3+ +3h2ooh- +h+==h2o

co3- +2h+ ==h2o+co2↑

1. Acid detection should be confirmed by iron and hydrogen production.

It is impossible to have as it should.

na2co3 + 2hcl === 2nacl + h2o + co2↑

Fe2O3 + 6HCl === 2FeCl3 + 3H2OHCL + NaOH ==== NaCl +H2OFE + 2HCl === FeCl2 + H2 From the above equation, it can be seen that there are at most 4 kinds of solutes: NaCl, FeCl3, NaCl, and FeCl2.

I can't see your diagram, but the idea of solving the problem is still very clear, mainly to figure out the sequence of the reactions in it: first, 2HCl+Na2CO3, 2NACl+H2O+CO2, and then CaCl2+Na2CO3 CaCO3 +2NaCl, bring the data in the coordinates into the two equations, and the calculation can be pulled.

Solution: (1) Let the mass of carbon dioxide formed when reacting with hydrochloric acid be y Na2CO3 + 2HCl 2NaCl + CO2 + H2O106 44yy=

2) When reacting with calcium chloride, the mass of sodium carbonate solution is Zna2CO3 + CaCl2 CaCO3 + 2NaCl106 100

z 1gz = , the mass of the sodium carbonate solution that actually participates in the reaction is .

Solution: (1) When reacting with hydrochloric acid, the mass of sodium chloride is x, and the mass of carbon dioxide is y

na2co3+2hcl═2nacl+co2↑+h2o106 117 44x y

117x=44yx=，y=

2) When reacting with calcium chloride, the mass of sodium carbonate solution is Z, and the mass of sodium chloride is W

na2co3+cacl2═caco3↓+2nacl106 100 117z• 1g w106z•

1001g=

117wz=，w=

The mass of the sodium carbonate solution that actually participates in the reaction is.

3) The mass fraction of sodium chloride in the resulting solution is: One 1g one.

Answer: (1) Carbon dioxide is generated.

2) The mass of the sodium carbonate solution that actually participates in the reaction is.

3) The mass fraction of sodium chloride in the resulting solution is:

This belongs to the chicken-rabbit same basket to ask the wheel state trembling problem, assuming that all are big ships, that is, 5 times 12 is equal to 60 60 minus 40 is equal to 20 20 divided by the closed comic with the difference of 5 minus 3 is equal to 10 is the number of small boats 12 minus 10 is the number of big ships So there are 2 big ships and 10 small ships are defeated.

It's all whole lines, which means that the number of people is a common multiple of 12 and 16, and the smallest common multiple is 48, which just matches the number of people in a class, so there are 48 people.

12＝2×2×3

The least common multiple of 12 and 16 is 2 2 2 2 3 48 This class has a minimum of 48 students.

The least common multiple of 12 and 16 is 48, so there are 48 students in this class.

12 Decomposition prime factor = 2 2 3

16 decomposition prime factor = 16 2 2 2 2

Least common multiple of 12 and 16 = 2 2 2 2 3 48 This class has a minimum of 48 students.

12,16 least common multiple 48

So the answer is 48

40×＝60÷1/3

A: A total of 180 small flags were made.

Design: Make a small flag x side.

x×[(1－1/3)÷2]＝40×

x/3＝60

x 180 A: A total of 180 small flags were made.

The number of noodles made in a day and a half = 40 * 3 = 120 noodles.

40x=120 x=3...Sky.

3*120=360 faces.

It's really interesting enough, the question is not finished!! o(∩_o~

0, for example, there is no birthday in January, and they all go to other months. The question is at least the least, then you say how many are in January.