Solubility products of Al(OH)3 and Zn(OH)2 are 8.5 × 10-23 and 1.8 × 10-4 respectively. If both Al3+ and Zn2+ ions are present in a solution, which one will be precipitated first on addition of NH4OH?
Al(OH)3
Zn(OH)2
Both (a) and (b)
None of these
In a reversible isothermal process, the change in internal energy is
zero
positive
negative
None of these
Based on the following thermochemical equations
H2O (g) + C(s) → CO (g) + H2 (g); H = 131 kJ
CO (g) + O2(g) → CO2 (g); H = -282 kJ
H2 (g) + O2 (g) → H2O (g); H =-242 kJ
C (s) + O2 (g) → CO2 (g); H = X kJ
the value of X will be
-393 kJ
-655 kJ
+393 kJ
+655 kJ
The first ionisation potential of Na, Mg, Al and Si are in the order
Na < Mg > Al < Si
Na > Mg > Al > Si
Na < Mg < Al > Si
Na > Mg > Al < Si
Elements of which group form anions most readily?
Oxygen group
Nitrogen group
Halogens
Alkali metals
Which of the following elements is present in red blood cells of man?
Fe
Ra
Co
None of these
A.
Fe
The red pigment of blood of man is haemoglobin which is a complex compound of iron (Fe). Actually heme part of haemoglobin contains Fe bound to the pyrole system, called porphin.