Advertisements
Advertisements
प्रश्न
Which of the following statements is not correct?
विकल्प
Copper liberates hydrogen from acids.
In its higher oxidation states, manganese forms stable compounds with oxygen and fluorine.
\[\ce{Mn^{3+}}\] and \[\ce{Co^{3+}}\] are oxidising agents in aqueous solution.
\[\ce{Ti^{2+}}\] and \[\ce{Cr^{2+}}\] are reducing agents in aqueous solution.
Advertisements
उत्तर
Copper liberates hydrogen from acids.
Explanation:
Copper does not liberate hydrogen from acids.
\[\ce{Cu + 2H2SO4 -> CuSO4 + SO2 + 2H2O}\]
\[\ce{3Cu + 8HNO3 -> 3Cu (NO3)2 + 2NO + 4H2O}\]
APPEARS IN
संबंधित प्रश्न
Account for the following:
Cr2+ is a strong reducing agent.
In 3d series (Sc to Zn), which element has the lowest enthalpy of atomisation and why?
Which is a stronger reducing agent, Cr2+ or Fe2+ and why?
Explain briefly how +2 state becomes more and more stable in the first half of the first row transition elements with increasing atomic number?
What are the characteristics of the transition elements and why are they called transition elements?
Which metal in the first series of transition metals exhibits +1 oxidation state most frequently and why?
Write balanced chemical equations for the conversion of `CrO_4^(2-)` to `Cr_2O_7^(2-)` in acidic medium and `Cr_2O_7^(2-)` to `CrO_4^(2-)`
in basic medium.
Why do transition metals exhibit higher enthalpy of atomization?
Give reasons for the following:
The transition metals generally form coloured compounds.
In lake test for Al3+ ions, there is the formation of coloured ‘floating lake’. It is due to ______.
Electronic configuration of a transition element X in +3 oxidation state is [Ar]3d5. What is its atomic number?
When a brown compound of manganese (A) is treated with \[\ce{HCl}\] it gives a gas (B). The gas taken in excess, reacts with \[\ce{NH3}\] to give an explosive compound (C). Identify compounds A, B and C.
Although \[\ce{Cr^3+}\] and \[\ce{Co^2+}\] ions have same number of unpaired electrons but the magnetic moment of \[\ce{Cr^3+}\] is 3.87 B.M. and that of \[\ce{Co^2+}\] is 4.87 B.M. Why?
A solution of \[\ce{KMnO4}\] on reduction yields either a colourless solution or a brown precipitate or a green solution depending on pH of the solution. What different stages of the reduction do these represent and how are they carried out?
On the basis of the figure given below, answer the following questions:
- Why Manganese has lower melting point than Chromium?
- Why do transition metals of 3d series have lower melting points as compared to 4d series?
- In the third transition series, identify and name the metal with the highest melting point.
Passing H2S gas into a mixture of Mn2+ and Ni2+, Cu2+, ions in an acidified aqueous solution precipitates.
Which of the following species has maximum magnetic momentum?
The disproportionation of \[\ce{MnO^{2-}_4}\] in acidic medium resulted in the formation of two manganese compounds A and B. If the oxidation state of Mn in B is smaller than that of A, then the spin-only magnetic moment (µ) value of B in BM is ______. (Nearest integer)
Which property of transition metals enables them to behave as catalysts?
Which of the following ions has the electronic configuration 3d6?
(Atomic number: Mn = 25, Co = 27, Ni = 28)
