Noble gases are used in discharge tubes to give different colours. Reddish-orange glow is due to
Ar
Ne
Xe
Kr
The correct order of acid strength is
HClO < HClO2 < HClO3 < HClO4
HClO4 < HClO < HClO2 < HClO3
HClO2 < HClO3 < HClO4 < HClO
HClO4 < HClO3 < HClO2 < HClO
A.
HClO < HClO2 < HClO3 < HClO4
Correct order of acid strength is
Acid strength oxidation number
Which of the following metals, Fe, Zn, Pb, Ag and Pt do not give a metal nitrate on treatment with concentrated HNO?
Fe and Zn.
Fe and Pt.
Pb, Ag and pt.
Fe, Ag and Zn.
The oxidation number of sulphur atoms in peroxomonosulphuric acid H2SO5 and peroxodisulphuric acid H2S2O8, respectively are:
+8 and +7
+6 and +6
+4 and +6
+3 and +3
When aqueous ammonia is added to green solution of nickel chloride, the colour changes to:
yellow
purple
violet
violet
Organophosphorus compounds are the most toxic insecticides. The common organophosphorus insecticides is:
Methoxy chlor
Dieldrin
Parathion
Malathion
In trimeta-phosphate ion, the number of 0 atom P-O-P bonds and unit negative charges are respectively:
6,6,3
3,6,3
9,3,3
9,6,3
Which of the following is the laboratory method for synthesis of nitric oxide?
Reaction of zinc with cold and dilute HNO3
Reaction of zinc with concentrated HNO3
Reaction of copper with cold and dilute HNO3
Heating NH4NO3