Which of the following pairs liberate gas a when they react with each other?(EAMCET 2005 M)

1) SiO₂, Na

2) Fused NaOH, C

3) Mg, B₂O₃

4) Mg, CO₂

Total number of structural isomers of 
[Co(NH₃)₆][Cr(CN)₆]

Why is boiling point of Cesium higher than that of Rubidium

 

which isomer mentioned in (a) is water soluble and why?

A gaseous mixture contains CO2 and CO the mass of the mixture is 200g and they are presenting equal fraction of moles . Find the total no. of O-atoms present in the mixture.