Answer:
sodium hexachloroplatinate(IV)- Na2[PtCl6]
dibromobis(ethylenediamine)cobalt(III) bromide- [Co(en)2Br2]Br
pentaamminechlorochromium(III) chloride-[Cr(NH3)5Cl]Cl2
Explanation:
The formulas of the various coordination compounds can be written from their names taking cognisance of the metal oxidation state as shown above. The oxidation state of the metal will determine the number of counter ions present in the coordination compound.
The number ligands are shown by subscripts attached to the ligand symbols. Remember that bidentate ligands such as ethylenediamine bonds to the central metal ion via two donors.
Answer : The correct option is, (B) 
Solution :
According to the Graham's law, the rate of effusion of gas is inversely proportional to the square root of the molar mass of gas.

or,
..........(1)
where,
= rate of effusion of unknown gas = 
= rate of effusion of oxygen gas = 
= molar mass of unknown gas = ?
= molar mass of oxygen gas = 32 g/mole
Now put all the given values in the above formula 1, we get:


The unknown gas could be carbon dioxide
that has approximately 44 g/mole of molar mass.
Thus, the unknown gas could be carbon dioxide 
2-ethyl-4,4 -dimethyl hex-1-ene.
The new volume of a 250 Ml sample of gas at 300k and 1atm if heated to 350 k at 1 atm is 291.67 Ml
<u>calculation</u>
This is solved using the Charles law formula since the pressure is constant.
that is V1/T1 = V2/T2 where,
V1 =250 ml
T1=300 K
V2=?
T2= 350 k
by making V2 the subject of the formula by multiplying both side by T2
V2= T2V1/T1
V2= (350 K x 250 ml) / 300K =291.67 Ml