Why do Zr and Hf show similar properties ?

1 Answer

Answer :

 Ans It is due to similar ionic size which due to lanthanide contraction . 

Related questions

Description : Explain the following , giving reason . (a) Transition metal and many of their compounds show paramagnetic behavior (b) The enthalpy of atomisation of the transition metal is high . (c) The Transition metal generally form coloured compounds . 

Last Answer : Ans(a) It is due to unpaired electrons . (b) It is due to strong metallic bond and additional Covalent bonds due to presence of unpaired electron in d- orbitals (c) It is due to presence of unpaired electrons ,they undergo d-d transition . 

Description : Why are Ti+2 and other transition metals and their ions paramagnetic ?

Last Answer :  Ans: These ions have unpaired electrons in d- subshell. 

Description : Why do transition metals have higher I.E than s –block elements ?

Last Answer : Ans: It is due to smaller atomic size than s-block elements , effective nuclear charge is more , terefore I.E is high.

Description : Why is K2Cr2O7 generally preferred over Na2Cr2O7 in a volumetric analysis .Give reason .

Last Answer : Ans : It is because Na2Cr2O7 is hygroscopic in nature that is why it absorbs moisture from atmosphere , therefore its standard solution can not be prepared .

Description : Why are lanthanoid colored and paramagnetic L

Last Answer : Ans It is due to presence of unpaired electrons, they are paramagnetic and they absorb light From visible region and undergoes f-f transition and radiate complementary colour . 

Description : Why Mn+2 is more stable than Mn+3 but Fe +3 is more stable than Fe+2 ?

Last Answer : Ans Mn+2 has half filled d- orbital ,therefore it is more stable than Mn+3 Fe+3 has half filled d- orbital, therefore it is more stable than Fe +2 . 

Description : Why are transition metal fluorides are ionic in nature where as chlorides and bromides are covalent in nature . 

Last Answer : Ans - It is because of fluorine is most electronegative where as Cl and Br are less electro negative . Greater the difference in electro negativity more will be ionic character .

Description : Why is Cu+1 diamagnetic and Cu +2 paramagnetic ?

Last Answer : It is because Cu+ does not have unpaired electrons where as Cu+2 has unpaired electrons in d-sub cell . 

Description : Why are Cr+ , Ag+ & Sc+3 Colour less ? 

Last Answer : Ans It is because they do not have unpaired electrons ,therefore can not under goes d-d transition .

Description : Why are transition metals and there compounds generally coloured ?

Last Answer : Ans It is due to present of unpaired electrons in transition metals and their ions , that is why they absorbed light from visible region and undergoes d-d transition and radiate complementary colour . 

Description : Why does V2O5 acts as catalyst ?

Last Answer : Ans : It is because V shows variable O.S . 

Description : What is an lanthanoid contraction ? What is its cause ? Give its consequences .

Last Answer : Ans The decrease in atomic and ionic size with increase in atomic no. in lanthanoid series is called lanthanoid contraction . The cause of lanthanoid contraction is poor shielding effect of d and f ... is close resemblance between elements of 4 d and 5 d transition series . due to similar ionic 

Description : Why Ce+3 Can be easily Oxidised to Ce+4 ?

Last Answer : Ans : It is because Ce+4 has stable electronic configuration . 

Description : Why do transition metals have high enthalpy of atomization ?

Last Answer :  Ans : it is due to strong metallic bonds and additional covalent bonds 

Description : What is the highest oxidation state shown by Cr. (24) , Mn(25) ?

Last Answer : Ans: Cr. Shows (+6) and Mn Shows (+7) Oxidation state .  

Description : Why are Zn , Cd , Hg are not regarded as transition metals ? 

Last Answer : Ans: It is because neither they nor their ions have incompletely filled d- orbitals . 

Description : What are d Block Elements ? 

Last Answer : Ans: Those elements in which d-orbital are progressively filled up are known as d-orbital.

Description : Application of d- & f- block elements

Last Answer : Application of d- & f- block elements:- 1. Iron and steel used in construction,as catalyst in Haber's process 2. CrO2 is used in magnetic tapes 3. Ni is in hydrogenation 4. W ( ... in contact process 9. Titanium is in nuclear reactions. 10. PdCl2 is in Wacker's process.

Description : General pivot point rotation can be expressed as a.T(zr,yr).R(θ).T(-zr,-yr) = R(xr,yr,θ) b.T(xr,yr).R(θ).T(-xr,-yr) = R(xr,yr,θ) c.T(xr,yr).R(θ).T(-xr,-yr) = R(zr,yr,θ) d.T(xr,yr).R(θ).T(-xr,-yr) = R(zr,yr,θ)

Last Answer : b.T(xr,yr).R(θ).T(-xr,-yr) = R(xr,yr,θ)

Description : What is the atomic number of Zr ?

Last Answer : The atomic number of Zr is 40

Description : Among the metals Ti,V,W,Zr th and Au the number of metals purified van arkel method are…….

Last Answer : Among the metals Ti,V,W,Zr th and Au the number of metals purified van arkel method are…….

Description : How many energy levels contain electrons in an atom of zirconium (Zr)?

Last Answer : 4

Description : Which among the following is used as a catalyst in the production of high octane fuels? (1) HNO3 (2) H2SO4 (3) HCl (4) HF

Last Answer : (2) H2SO4 Explanation: Sulfuric acid is used as a catalyst for refining and for producing alkylate, an essential component of highoctane fuel. The hydrocarbon molecules are reformed into more complex molecules with a higher octane rating value.

Description : Glass is soluble in - (1) H2SO4 (2) HCIO4 (3) HNO3 (4) HF

Last Answer : (4) HF Explanation: Hydrofluoric acid is a highly corrosive acid, capable of dissolving many materials, especially oxides. Its ability to dissolving lass has been known since the 17th century. It is a solution of hydrogen fluoride in water and is represented by HF.

Description : Interveinal necrotic spots on leaves appear due to – (1) HF injuly (2) SO2 injury (3) NO2 injury (4) O3 injury

Last Answer : (2) SO2 injury Explanation: Injury caused by sulphur oxides show interveinal necrotic areas that are light tan to white. Uninjured tissue new to the veins remains green.

Description : Arrange the following in order of decreasing reactivity towards alkanes. HCl, HBr, HI, HF

Last Answer : Ans. HI> HBr> HCl >HF

Description : Use the information and data given below to answer the questions Stronger intermolecular forces result in higher boiling point Strength of London forces increases with the number of electrons in the molecule ... here? (c) Why is the boiling point of HF highest while that of HCl lowest?

Last Answer : Ans :( a) In the molecules HCl, HBr and HI, dipole-dipole interaction and London forces are present. (b) Dipole moment of HCl > HBr > HI but boiling point of HCl < HBr

Description : Name two intermolecular forces that exist between HF molecules in liquid state.

Last Answer : Ans. Dipole-dipole interaction and hydrogen bonding.

Description : 36. Aluminium is extracted from alumina (Al2O3 ) by electrolysis of a molten mixture of : (1) Al2O3 + KF + Na3AlF6 (2) Al2O3 + HF + NaAlF4 (3) Al2O3 + CaF2 + NaAlF4 (4) Al2O3 + Na3AlF6 + CaF2

Last Answer : Al2O3 + Na3AlF6 + CaF2

Description : Interveinal necrotic spots on leaves appear due to (1) HF injury (2) SO2 injury (3) NO2 injury (4) O3 injury

Last Answer : SO2 injury

Description : Which among the following is used as a catalyst in the production of high octane fuels? (1) HNO3 (2)H2 SO4 (3) HCl (4) HF

Last Answer : H2 SO4

Description : Glass is soluble in (1) H2 SO4 (2) HClO4 (3) HNO 3 (4) HF

Last Answer : HF

Description : Which Canon Vixia HF S10 camcorder battery will last more than two hours?

Last Answer : The longest lasting battery will have the highest current rating - the mAh rating. You might need to consider an external battery pack. Both are common on eBay and similar places. Leaving it to ... doesn't leave much time for other than direct purchase - possibly through the duty free stores.

Description : What memory card do I have to use for the Canon Vixia HF S10 camcorder?

Last Answer : SDHC

Description : Is the Canon Vixia HF S10 already set to HD?

Last Answer : answer:The Vixia HF S10 is rated at 1080p so yes, it is HD However, YouTube HD is only capable of 720p resolution (still HD) and recommends these setting for your video: H.264, MPEG-2 ... you have a fast internet connection, otherwise you might find that videos don't play as quickly or smoothly.

Description : New Canon Vixia HF S10, how many characters is there on the serial number and how to fix ImageMixer problem?

Last Answer : You might be entering it incorrectly. Does it have dashes or spaces between numbers that you entering or not entering?

Description : What is the full form of 'HF' ? -How To ?

Last Answer : The full form of 'HF' is High Frequency

Description : What is the atomic number of Hf ?

Last Answer : The atomic number of Hf is 72

Description : More powerful than HF, HCl, HBr ?

Last Answer : HF is more powerful.

Description : Assertion :-HCl is more polar than HF. Reason :- Cl has more E.N. than F.

Last Answer : Assertion :-HCl is more polar than HF. Reason :- Cl has more E.N. than F. A. If both ... Reason is False. D. If both Assertion & Reason are false

Description : Which of the following hydrogen halides react with `AgNO_3` to give a precipitate that dissolves in hypo solution ? (I)HCl (II)HF (III)HI (IV)HBr

Last Answer : Which of the following hydrogen halides react with `AgNO_3` to give a precipitate that dissolves in hypo solution ? (I) ... II),(I) D. (II),(IV),(III)

Description : The number of cornpounds.’elements oxidised by `XeF_2` among following is: HF, HBr, HCl, HI, `NH_3, CrF_2`, Pt, `S_8`

Last Answer : The number of cornpounds.’elements oxidised by `XeF_2` among following is: HF, HBr, HCl, HI, `NH_3, CrF_2`, Pt, `S_8`

Description : `DeltaH_"vaporisation"` (KJ/mol) are given for the hydrides of halogens in the following graph. The hydride HF will correspond to

Last Answer : `DeltaH_"vaporisation"` (KJ/mol) are given for the hydrides of halogens in the following graph. The hydride HF will ... . (B)Q C. (C)R D. (D)S

Description : Find the maximum energy that a beta particle can have in the following decay `^176 Lu rarr ^176 Hf + e + vec v`. Alomic mass of `^176 Lu` is `175.9426

Last Answer : Find the maximum energy that a beta particle can have in the following decay `^176 Lu rarr ^176 Hf + e + ... and that of `^176 Hf` is `175.941420 u`.

Description : `XeF_(n)` dissolves in HF according to the reaction `xeF_(n) +HF rarr [XeF_(n-1)]^(+) [HF_(2)]^(-)`. What is the value of n?

Last Answer : `XeF_(n)` dissolves in HF according to the reaction `xeF_(n) +HF rarr [XeF_(n-1)]^(+) [HF_(2)]^(-)`. What is the value of n?

Description : `XeF_(2)+H_(2)O overset("alkali")rarr A +HF +O_(2)`, then A is

Last Answer : `XeF_(2)+H_(2)O overset("alkali")rarr A +HF +O_(2)`, then A is A. `XeO_(3)` B. `XeO_(4)` C. `XeO_(2)F_(2)` D. `Xe`

Description : `XeF_(6)` dissolves in anhydrous `HF` to give a good conducting solution which contains:

Last Answer : `XeF_(6)` dissolves in anhydrous `HF` to give a good conducting solution which contains: A. `H^(+)` and ` ... +)` and `F^(-)` ions D. none of these

Description : How is a Hf related to the H of a reaction?

Last Answer : The H(reaction) is the difference between Hf,products and Hf reactants

Description : What is H20 HF NH3?

Last Answer : H20 is water.HF is hydrogen fluoride.NH3 is ammonia.

Description : How is a Hf related to the H of a reaction?

Last Answer : The H(reaction) is the difference between Hf,products and Hf reactants