Multiple Choice QuestionsThe concentration of fluoride, lead, nitrate and iron in a water sample from an underground lake was found to be 1000 ppb, 40 ppb, 100 ppm and 0.2 ppm, respectively. This water is unsuitable for drinking due to the high concentration of:
Lead
Nitrate
Iron
Iron
B.
Nitrate
This water unsuitable for drinking due to the high concentration of nitrate. In drinking water, maximum permissible concentration of
Lead = 50 ppm
Nitrate = 50 ppm
Iron = 0.2 ppm
Fluoride = 1 ppm
The main oxides formed on combustion of Li, Na and K in excess of air are, respectively:
LiO2, Na2O2 and K2O
LiO2, Na2O2 and KO2
LiO, Na2O2 and KO2
LiO, Na2O2 and KO2
For a linear plot of log (x/m) versus log p in a Freundlich adsorption isotherm, which of the following statements is correct? (k and n are constants)
1/n appears as the intercept.
Only 1/n appears as the slope.
log (1/n) appears as the intercept.
log (1/n) appears as the intercept.
18 g glucose (C6H12O6 ) is added to 178.2 g water. The vapor pressure of water (in torr) for this aqueous solution is:
76.0
752.4
759.0
759.0
Decomposition of H2O2 follows a first order reaction. In fifty minutes the concentration of H2O2 decreases from 0.5 to 0.125 M in one such decomposition. When the concentration of H2O2 reaches 0.05 M, the rate of formation of O2 will be:
6.93×10−4 mol min−1
2.66 L min−1 at STP
1.34×10−2 mol min−1
1.34×10−2 mol min−1
The pair having the same magnetic moment is:
[At. No. : Cr=24, Mn=25, Fe=26, Co=27]
[Cr(H2O)6 ]2+ and [Fe(H2O)6 ]2+
[Mn(H2O)6 ]2+ and [Cr(H2O)6 ]2+
[CoCl4 ]2− and [Fe(H2O)6 ]2+
[CoCl4 ]2− and [Fe(H2O)6 ]2+
Which one of the following ores is best concentrated by froth flotation method?
Siderite
Galena
Malachite
Malachite
The pair in which phosphorous atoms have a formal oxidation state of +3 is:
Pyrophosphorous and hypophosphoric acids
Orthophosphorous and hypophosphoric acids
Pyrophosphorous and pyrophosphoric acids
Pyrophosphorous and pyrophosphoric acids
Which one of the following complexes shows optical isomerism?
cis[Co(en)2Cl2]Cl
trans[Co(en)2Cl2]Cl
[Co(NH3)4Cl2 ]Cl
[Co(NH3)4Cl2 ]Cl
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