Which two of the following salts are used for preparing iodized salt?
(i) KIO3, (ii) KI, (iii) I2, (iv) HI
(i) and (ii)
(i) and (iii)
(ii) and (iv)
(iii) and (iv).
The Ca2+ and F- are located in CaF2 crystal, respectively at face centred cubic lattice points and in
tetrahedral voids
half of tetrahedral voids
octahedral voids
half of octahedral voids
A 5% solution (by mass) of cane sugar in water has freezing point of 271 K and freezing point of, pure water is 273.15 K. The freezing point of a 5% solution (by mass) of glucose in water is
271 K
273.15 K
269.07 K
277.23 K.
The products formed when an aqueous solution of NaBr is electrolysed in a cell having inert electrodes are
Na and Br2
Na and O2
H2, Br2 and NaOH
H2 and O2.
Assertion : for Mn3+/Mn2+ is more positive than Cr3+/Cr3+
Reason : The third ionization energy of Mn is larger than that of Cr.
If both assertion and reason are true and reason is the correct explanation of the assertion.
If both assertion and reason are true but reason is not the correct explanation of the assertion.
If assertion is true, but reason is false.
Both assertion and reason are false statements.
B.
If both assertion and reason are true but reason is not the correct explanation of the assertion.
It is known that the value of becomes more negative clown the series. As the chromium is present below in electrochemical series than Mn, so Mn has more positive value than Cr.
Mn 3d5 4s2, Mn 3d5 4
Cr 3d5 4s1 Cr 3d4 4
For elimination or one electron from Mn2+, more energy is required due to its stable configuration. That is why third ionization energy of Mn is larger than Cr.
Assertion : K2Cr2O7 is used as primary standard in volumetric analysis.
Reason : It has a good solubility in water.
If both assertion and reason are true and reason is the correct explanation of the assertion.
If both assertion and reason are true but reason is not the correct explanation of the assertion.
If assertion is true, but reason is false.
Both assertion and reason are false statements.
Assertion : According to transition state theory, for the formation of an activated complex, one of the vibrational degrees of freedom is converted into a translational degree of freedom.
Reason: Energy of the activated complex is higher than the energy of reactant molecules.
If both assertion and reason are true and reason is the correct explanation of the assertion.
If both assertion and reason are true but reason is not the correct explanation of the assertion.
If assertion is true, but reason is false.
Both assertion and reason are false statements.
Assertion : Sb2S3 is not soluble in yellow ammonium sulphide.
Reason : The common ion effect due to S2- ions reduces the solubility of Sb2S3.
If both assertion and reason are true and reason is the correct explanation of the assertion.
If both assertion and reason are true but reason is not the correct explanation of the assertion.
If assertion is true, but reason is false.
Both assertion and reason are false statements.