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.
<h3><u>Explanation</u>:</h3>
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.
Option (a) is correct.
A reducing agent is the one which loses electrons to other substance.
Here, Zn has oxidation number 0 in the L.H.S of the equation, but on R.H.S its oxidation number is +2 i.e. it Zn has donated two of its electrons to

.
Hence, Zn is the reducing agent here.
Answer: Heat of vaporization is 41094 Joules
Explanation:
The vapor pressure is determined by Clausius Clapeyron equation:

where,
= initial pressure at 429 K = 760 torr
= final pressure at 415 K = 515 torr
= enthalpy of vaporisation = ?
R = gas constant = 8.314 J/mole.K
= initial temperature = 429 K
= final temperature = 515 K
Now put all the given values in this formula, we get
![\log (\frac{515}{760}=\frac{\Delta H}{2.303\times 8.314J/mole.K}[\frac{1}{429K}-\frac{1}{415K}]](https://tex.z-dn.net/?f=%5Clog%20%28%5Cfrac%7B515%7D%7B760%7D%3D%5Cfrac%7B%5CDelta%20H%7D%7B2.303%5Ctimes%208.314J%2Fmole.K%7D%5B%5Cfrac%7B1%7D%7B429K%7D-%5Cfrac%7B1%7D%7B415K%7D%5D)

Thus the heat of vaporization is 41094 Joules
Answer:
The two would end up repelling each other very strongly and more energy would ultimately be required to keep the metal-ligand system in place
Explanation:
A complex is made up a central metal atom or ion and ligands. Ligands are lewis bases and they possess lone pairs of electrons. A complex is formed when electrons are donated from ligand species to metals.
However, if the ligand has a negative charge at a particular location and we try to put electrons from the metal near the electrons from the ligand, the two would end up repelling each other very strongly and more energy would ultimately be required to keep the metal-ligand system in place.