Which of the following is an example of a double-displacement reaction?

AlCl3 + 3 NaOH → Al(OH)3 + 3 NaCl

Na2O + H2O → 2 NaOH

CuCO3 → CuO + CO2

None of the above are examples of double-displacement.

A

Which of the following is a double-displacement reaction?

2 KClO3 → 2 KCl + 3 O2

Zn + 2 HCl → ZnCl2 + H2

Fe + S → FeS

None of the above are examples of double-displacement.

D

Which of the following is a double-displacement reaction?

4P + 5O2 2P2O5

6NaNO3 6NaNO2 + 3O2

2C8H18 + 25O2 16CO2 + 18H2O

H2SO4 + 2NaOH Na2SO4 + 2H2O

C

What would most likely be the products of the double-displacement reaction between AgNO3 and NaCl ?

Ag + NaNO3

AgCl + Na

AgCl + NaNO3

The reaction would not occur because Al is lower on the activity series than Na.

C

1 answer

I believe #3 is wrong. The others are ok.
C is a combustion reaction. D is the double displacement.