The following groups of ions must coexist in large quantities in solution is () The following groups of ions must coexist in large quantities in solution is () A.H+、Cl-、OH- B.H+、SO42-、CO32-C.Ba2+、H+、SO42- D.Cu2+、Na+、NO3-

The following groups of ions must coexist in large quantities in solution is () The following groups of ions must coexist in large quantities in solution is () A.H+、Cl-、OH- B.H+、SO42-、CO32-C.Ba2+、H+、SO42- D.Cu2+、Na+、NO3-

If you choose D, those that can coexist in large numbers cannot react
A.H+ +OH-=H2O
B.2H+ +CO32-=H2O+CO2↑
C.Ba2+ +SO42-=BaSO4↓
D. Can coexist

Complete the following chemical equations to indicate which are chemical reactions; Those are decomposition reactions: ① Reaction of zinc with dilute sulfuric acid to produce hydrogen (at the same time, ZnSO4 is generated):____________________ ② Re combustion of iron wire in pure oxygen:____________________________________________ ③ Methane burns in the air to produce carbon dioxide and water:______________________________ ④ Water generates hydrogen and oxygen when energized:__________________________________ Among the above reactions, __ belongs to the combination reaction and _ belongs to the decomposition reaction

Zn+H2SO4====ZnSO4+H2↑
light
3Fe+2O2====Fe3O4
light
CH4+2O2====CO2+2H2O
Electrify
2H2O====2H2↑+O2↑
Chemical reaction: 2; Decomposition reaction: 4

Use the following substances to list two chemical equations for decomposition reaction and two for combination reaction Fe, H2O, H2, O2 and KMnO4

2kmno4 = heating = k2mno4 + MnO2 + O2 ↑ decomposition
2H2O = power on = 2h2 ↑ + O2 ↑ decomposition
2h2 + O2 = ignition = 2H2O combination
3Fe + 2O2 = ignition = Fe3O4 combination

2. Complete the following chemical equations to indicate which are chemical reactions and which are decomposition reactions? 1! Zinc reacts with dilute sulfuric acid to produce hydrogen [and ZnSO4 is also generated] The iron wire burns in pure oxygen 3 methane burns in the air to produce carbon dioxide and water: 4 water generates hydrogen and oxygen when energized:

1 replacement Zn + H2SO4 = ZnSO4 + H2
2Fe + 2O2 = Fe3O4 ignition condition
3 nothing is ignited under the condition of C2H4 + 3O2 = 2co2 + 2H2O
4. Power on under the condition of decomposition 2H2O = 2h2 + O2

Write the chemical equations for the conversion between the following substances. Which of them are chemical reactions? Which are decomposition reactions? ④ ① ② CO←C→CO2←CaCO3 ↑③ H2CO

1. C + O2 = ignition = CO2 combination reaction
2、CO2+Ca(OH)2=CaCO3+H2O
3. H2CO3 = = H2O + CO2 ↑ (decomposition reaction)
4. 2C + O2 = incomplete combustion = 2CO combination reaction
2C + CO2 = heating = 2CO combination reaction

Write the chemical equations for the transformation between the following substances. Which of them belong to the chemical reaction? Which are decomposition reflections? CO←C→CO2←CaCO3←H2CO3 Thank you ` ` please help me solve it right away ` ` I'm waiting to do it!

C + O2 = = ignition = = CO2 combination reaction
2C + O2 = = ignition = = 2Co (insufficient oxygen) combination reaction
CaCO3 = = high temperature = = CaO + CO2 decomposition reaction
H2CO3 + Ca (OH) 2 ==== CaCO3 precipitation + 2H2O double decomposition reaction