The following groups of substances can coexist in large quantities in solution

a. Sodium hydroxide and copper sulfate cannot coexist, which will form a blue precipitate of copper hydroxide (difficult to ionize);

b. Calcium hydroxide and hydrochloric acid cannot coexist, and water (weak electrolyte) will be generated;

d. Sodium carbonate hydrochloric acid cannot coexist, and will generate water (difficult to ionize) and carbon dioxide gas (volatile).

The answer is C.

The so-called coexistence of a large number of substances means that there is no reaction in the solution to produce other substances, and generally speaking, there is no metathesis reaction.

The metathesis reaction occurs when two compounds exchange groups to form new compounds, and the product contains a precipitate, gas or water (that is, a weak electrolyte), and the reaction can occur.

2NaOH+CuSO4====Cu(OH)2+Na2SO4 in A, precipitate is generated, reaction occurs, and cannot coexist.

Ca(OH)2+2HCl*****2H2O+CaCl2 in B, water is generated, reacts and cannot coexist.

No matter how the three substances in C are combined, gas, water and precipitation will not be formed, so they can coexist, and C is chosen

In D, Na2CO3 + HCl = = = CO2 + H2O + 2NaCl produces gas and undergoes metathesis reaction, so it cannot coexist.

Select Ca: sodium hydroxide and copper sulfate to generate precipitated Cu(OH)2B: calcium hydroxide and HCl acid-base neutralization reaction.

d: Sodium carbonate and hydrochloric acid metathesis reaction.

na2co3 + hcl = 2nacl + h2o + co2（g）

For example, Ca(OH)2 in B and HCl do not coexist with acid and carbonate, and CO2 will be generated

For example, sodium carbonate and hydrochloric acid.

There are insoluble substances that are not common in the formation of precipitates, and sodium hydroxide and copper sulfate in a form of copper hydroxide precipitate.

Insoluble does not coexist, for example, if I replace the hydrochloric acid in b with sodium hydroxide, it cannot be in large quantities.

coexist because calcium hydroxide is slightly soluble.

That's all.

will generate Cu(OH)2 with CuSO4

CuSO4+2NaOH=Cu(OH)2+Na2SO4 will react with Ca(OH)2.

Ca(OH)2+2HCl=CaCl2+2H2O reacts with Na2CO3 to form CO2 and NaCl

Na2CO3+2HCl=2NaCl+CO2+H2OC terms can coexist.

In CA, 2NaOH+CuSO4===Cu(OH)2+Na2SO4, and NaOH and CuSO4 do not coexist.

In B, 2HCl+Ca(OH)2===CaCl2+2H2O, HCl and Ca(OH)2 do not coexist.

In D, Na2CO3+2HCl===CO2+H2O+2NaCl, and HCl and Na2CO3 do not coexist.

It will form a Cu(OH)2 precipitate with CuSO4.

It reacts with Ca(OH)2.

It reacts with Na2CO3 to form CO2 and NaCl

Solution: A. Because HCL and Ca(OH)2 can exchange components with each other in the solution to form calcium chloride and water, they cannot coexist in large quantities, so the option is wrong

b. Because K2CO3 and H2SO4 can exchange components with each other in the solution to form potassium sulfate, water, and carbon dioxide, they cannot coexist in large quantities, so the option is wrong

c. Because BaCl2 and CuSO4 exchange components with each other in the solution to form barium sulfate precipitate and copper chloride, they cannot coexist in large quantities, so the option is wrong

D. Because KNO3, NaOH and Na2CO3 exchange components in the solution and cannot generate precipitation, gas and water, and can coexist in large quantities in the solution, the choice is correct

HCL and Ca(OH)2 cannot coexist in large quantities in DA.

K2CO3 and H2SO4 cannot coexist in large quantities in B.

In C, BaCl2 and CuSO4 cannot coexist in large quantities.

Answer: Cause: Cuso4 NaOH in option A reacts in water to form Cu(Oh)2 precipitate which is a metathesis reaction and therefore cannot coexist.

Option B metathesis reaction generates a BASO4 precipitate, so it cannot coexist.

Option C reacts to produce CO2 gas and water. It is a metathesis reaction and cannot coexist.

Option d The two substances do not react, so they can coexist.

This question mainly uses the knowledge of metathesis reactions to generate precipitation, gas, and water, which cannot coexist in water.

In fact, the reason for this kind of problem is very simple, these substances cannot react with each other to coexist.

a Copper sulphate and sodium hydroxide react to form copper hydroxide precipitates, so they cannot coexist.

b Barium nitrate and sodium sulfate react to form barium sulfate precipitate, so they cannot coexist.

c Sodium carbonate and hydrochloric acid can also react to form sodium chloride, water and carbon dioxide, so they cannot coexist.

d cannot react, so it can coexist.

So choose D for this question

Remember, not being able to react is being able to coexist.

Thank you!!!

Answer: d.

Explanation: a. Cu(OH)2 suspension will be formed.

b. BaSO4 precipitation.

C. Na2CO3 is alkaline, HCl is an acid, and acid-base neutralization reaction will occur to produce CO2, NaCl, and H20

D. Cakno3 is nitrate, soluble in water, CaCl2 Kno3 exists in ionic form in aqueous solution, and can coexist in large quantities.

Choose C, can coexist in large quantities, but cannot react.

c.No reaction occurs.

A Cu(OH)2 is formed and precipitated.

b Formation of water acid-base neutralization.

c Wood has precipitated gases, etc.

d has CO2 gas selection c

Answer: Ca, the generation of barium sulfate precipitate trace detection.

B, H2SO4 and Na2CO3 were buried into CO2 gas.

D, NaOH, H2SO4 and HCl undergo acid-base neutralization reactions.

Choosing a can coexist in large quantities, which means that the substances do not react. The reactions involved in these two items are metathesis reactions, so as long as the wood is produced by gas, precipitation, and water after the ions are combined, the reaction does not occur, then it meets the requirements of the topic.

In option B, Fe3+ and OH- combine to form iron hydroxide precipitates, so they cannot coexist in large quantities.

The substances in the selected AA are all ionic in the aqueous solution and do not reflect each other.

b. Nitric acid and sodium hydroxide acid-base neutralization.

c Magnesium sulfate and potassium hydroxide will produce magnesium hydroxide, insoluble substances, will precipitate d d sodium carbonate and hydrochloric acid reaction, to generate carbon dioxide and water.

a.Because all the other options will react.