The Periodic Table at a Glance
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Single Correct Answer Type Question 1. What is its atomic number? Which of the following is correct? Metallic radii of some transition elements are given below. Which of these elements will have highest density? Decreases in metallic radius coupled with increase in atomic mass results in increase in density of metal.
Generally, transition elements form coloured salts due to the presence of unpaired electrons. Which of the following compound will be coloured in solid state? On addition of small amount of KMnO 4 to concentrated H 2 SO 4a green oily compound is obtained which is highly explosive in nature.
Identify the compound from the following: The magnetic binary metal halides of the d-block elements of elements depend on the presence of unpaired electrons. Identify the configuration of transition element, which shows the highest magnetic moment.
Since, 3d 5 has 5 unpaired electrons hence highest magnetic moment. Which of the following oxidation state is common for all lanthanoids? Which of the following reactions are disproportionation reactions? There are 14 elements in actinoid series.
Which of the following element does-not belong to this series? KMnO 4 acts as an oxidizing agent in acidic medium. The number of moles of KMn04 that will be needed to react with one mole of sulphide binary metal halides of the d-block elements in acidic solution is Solution: Which of the following is amphoteric oxide?
In lower oxides, the basic character is predominant while in higher oxides, the acidic character is predominant. Gadolinium belongs to 4f series.
Its atomic number is Which of the following is the correct electronic configuration of gadolinium? Interstitial compounds are formed when small atoms are trapped inside the crystal lattice of metals. Which of the following is not the characteristic property of interstitial compounds? The magnetic moment is associated with its spin angular momentum and orbital angular momentum.
KMn04 acts as an oxidizing agent in alkaline medium. Which of the following statement is not correct? The reaction is given below. Binary metal halides of the d-block elements zirconium belongs to 4d transition series and hafnium to 5d transition series even then they show similar physical and chemical properties because a both belong to d-block b both have same number of electrons c both have similar atomic radius d both belong to the same group of the periodic table Solution: More than One Correct Answer Type.
Generally, transition-elements and their salts are coloured due to the presence binary metal halides of the d-block elements unpaired electrons in metal ions. Which of the following compounds are coloured? Transition elements show magnetic moment due to spin and orbital motion of electrons.
Which of the following metallic ions have almost same spin only magnetic moment? Hence they have almost same spin only magnetic moment. Which of the following actinoids have one electron in 6d orbital? Which of the following ions show higher spin only magnetic moment value? Transition elements form binary compounds with halogens. Which of the following elements will form MF3 type compounds? The ability of fluorine to stabilize the highest oxidation state is due to higher lattice energy in CoF 3 and higher bond enthalpy for the higher covalent compound like CrF 6.
Which of the following will not act as oxidizing agents? As higher oxidations states of W and Mo are more stable, therefore they will not act as oxidizing agents. Why does copper not replace hydrogen from acids? Therefore, copper does not liberate hydrogen from acids. Why first ionization enthalpy of Cr is lower than that of Zn? The electronic configuration of chromium and zinc are respectively: Transition elements show high melting points. The high melting points of transition metals are due to strong metallic bonds between the atoms of these elements.
This is because of involvements of greater number of electrons in the interatomic metallic bonding from n — 1 d orbitals in addition to ns electrons. Explain the reaction with the help of chemical equation. This is given by the equation.
CuCl 2 is more stable than Cu 2 Cl 2. The compounds A, B and C are as follows: Although fluorine is more electronegative than oxygen, but the ability best trading platform canada oxygen to stabilize higher oxidation states exceeds that of fluorine.
The electronic configuration of fluorine is 1s 2 2s 2 2p 5. Thus it can form only one bond as it has only one binary metal halides of the d-block elements electron. Electronic configuration of oxygen is 1s 2 2s 2 2p 6 3s 2 3p 6. It may be mentioned that oxygen also has vacant d-orbitals along with two 3p orbitals containing single electron.
Thus, oxygen has greater bond formation capacity. Binary metal halides of the d-block elements other words, it has greater ability to stabilize higher oxidation states.
Ionisation enthalpies of Ce. Pr and Nd are higher than Th, Pa and U. It is because in the beginning when 5f-orbitals begin to be occupied, they penetrate less into inner core electrons. Thus, 5f-electrons are more effectively shielded from the nuclear charge than 4f electrons in the lanthanide series. Therefore, outer electrons are less firmly held and thus these electrons are available for bonding in actinoids and their removal is much more easier. Although Zr belongs to 4d and Hf belongs to 5d transition series but it is quite difficult to separate them.
Zr, a member of Ad series and Hf, a member of 5d series, belong to same group. They are chemically so similar that their separation is difficult. This is due to the fact that both have same size due to lanthanide contraction. The radii of these elements are pm Zr and pm Hf. The electronic configuration of Ce is -4f 1 5d 1 6s 2. The acidified solution of KMnO 4 acts as an oxidising agent. Explain why does this happen? On heating with alkalies, the orange colour of dichromate solution changes to yellow due to the formation of chromate ions.
A solution of KMnO 4 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? KMnO 4 acts as an oxidising agent in alkaline, neutral and acidic mediums, i.
The second and third rows of tfansition elements resemble each other much more than they resemble the first row. Due to lanthanide contraction, the atomic radii of the second and third row transition binary metal halides of the d-block elements are almost same. Therefore, they resemble each other much more as compared to first row elements. However, Zn exhibits a lower value of ionization enthalpy because a stable 3d 10 configuration is attained after losing two electrons.
The halides of transition elements become more covalent with increasing oxidation state of the metal. As the oxidation state of the element increases, its charge increases.
According to Fajans rules, as the charge of the metal ion increases covalent character increases because the positively charged cation attracts the electron cloud on the anion towards itself. While filling up of electrons in the atomic orbitals, the 4s orbital is filled before the 3d-orbital but reverse happens during the ionization of the atom. Ionisation enthalpy is responsible for the ionisation of atom.
So electrons are removed from 4s orbital prior to 3d. Reactivity binary metal halides of the d-block elements transition elements decreases almost regularly from Sc to Cu.
Reactivity of an element is dependent on the value of ionization enthalpy. In moving from Sc, the first element to Cu, the ionization enthalpy increases regularly. Therefore, the reactivity degreases as we move from Sc to Cu. In the following questions, a statement of Assertion A followed by a statement of Reason R is given. Choose the correct answer out of the following choices: Separation of Zr and Hf is difficult.
Because Zr and Hf lie in the same binary metal halides of the d-block elements of the periodic table. Actinoids form relatively less stable complexes as compared to lanthanoids. Actinoids can utilize their 5d orbitals along with 6d orbitals in bonding but binary metal halides of the d-block elements do not use their 4f orbital for bonding.