which formula represents a double displacement reaction?
ca(oh)2(s) mc009-1.jpg cao(s) + h2o(g)
c2h5oh(i) + o2(g) mc009-2.jpg co2(g) + h2o(g)
zn(s) + 2hcl(aq) mc009-3.jpg zncl2(aq) + h2(g)
pb(no3)2(aq) + 2hcl(aq) mc009-4.jpg 2hno3(aq) + pbcl2(s)

Explanation: 1.

This is an example of decomposition reaction in which one reactant gives two or more than two products on absorption of energy.

2.

This is an example of combustion reaction in which hydrocarbon burns in the presence of oxygen to form carbon dioxide, water and energy.

3.

This is an example of single replacement reaction in which a more reactive element displaces a less reactive element from its salt solution.

4.

This is an example of a double displacement reaction in which exchange of ions take place.

what's the

a  solution  is always transparent, light passes through with no scattering from solute particles which are molecule in size. the  solution  is homogeneous and does not settle out. a colloid is intermediate between asolution  and a  suspension. while asuspension  will separate out a colloid will not.