2nd part of the other one plz help

18. Reaction will occur.

19. Reaction Will occur.

20. Reaction will occur.

21. Reaction will occur.

22. Reaction won't occur.

23. Reaction will occur.

24. Reaction will occur.

25. Reaction won't occur.

The reaction rate of the metals with water, steam, acid, or hydroxides or their inert behavior towards them are noted in the metal activity series.

It contains all the metals one after the other which and the upper metal can replace the lower metal from its salt.

Calcium can replace hydrogen from acid, so the reaction will occur in 18. The products formed are calcium phosphate and hydrogen gas.

Chlorine is more reactive than bromine. So it can replace bromine from its salt to from bromine gas and magnesium chloride.

Aluminium can replace iron from its salt. So it will form aluminium oxide and iron metal. This reaction is used to obtain iron from ores.

Zinc can replace hydrogen from acid. So the products will be zinc chloride and hydrogen gas.

Chromium cannot displace hydrogen form water. So the reaction won't occur.

Tin can replace hydrogen form acid. So the reaction will proceed.

Magnesium will replace platinum from its salt. So magnesium oxide and platinum will form.

Bismuth cannot replace hydrogen from acid. So the reaction won't proceed.

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.

the answer your looking for is c).