Practice free Chemistry NEET multiple-choice questions online with instant answers and detailed explanations. No login required.
Hoope's process is used in the refining of:
It is a method for refining of Al.
The cell used in this process consists of an iron tank lined with carbon at the bottom. A molten alloy of copper, crude aluminium and silicon is used as the anode. It forms the lowermost layer in the cell. The middle layer consists of molten mixture of fluorides of sodium, aluminium and barium (cryolite + BaF2). The uppermost layer consists of molten aluminium. A set of graphite rods dipped in molten aluminium serve as the cathode. During electrolysis, Al3+ ions from the middle layer migrate to the upper layer, where they are reduced to aluminum by gaining 3 electrons. Equal numbers of Al3+ ions are produced in the lower layer. These ions migrate to the middle layer. Pure aluminium is tapped off from time to time. The Hoopes process gives about 99.99% pure aluminium.
Aluminium becomes passive in nitric acid because it:
Surface of forms in nitric acid and becomes passive.
Which is used as mordant?
It is an use of alum.
A mordant or dye fixative is a substance used to set (i.e. bind) dyes on fabrics by forming a coordination complex with the dye, which then attaches to the fabric (or tissue).[1] It may be used for dyeing fabrics or for intensifying stains in cell or tissue preparations. Although mordants are still used, especially by small batch dyers, it has been largely displaced in industry by directs.[2]
Hybridisation of boron in diborane is:
-hybridisation, but four bonds are neither linear nor in one plane.
does not exist as dimer but exist as dimer because:
To form the dimer, the planar molecule has to assume a sort of tetrahedral orientation around the boron atom, as it happens in the case of Al2Cl6, which is the dimer of AlCl3 in the vapour state. But, in all the three boron halides, significant amount of pi-pi interaction occurs between the vacant p-orbital of boron and the filled p-orbitals of the halogens. Such interaction in the three trihalides increases in the order BBr3 < BCl3 < BF3
Reactivity of borazole is greater than that of benzene because:
Borazole is polar due to bond; benzene is non-polar due to bonds.
Inorganic benzene is:
Inorganic benzene is borazine, which has the chemical formula B3N3H6. It is an inorganic compound with a planar ring structure similar to that of benzene, but with alternating boron and nitrogen atoms instead of carbon atoms.
Fluorine is more electronegative than either boron or phosphorus. What conclusion can be drawn from the fact that has no dipole moment but has?
This give rise to net dipole moment zero in . .
In , which statement is incorrect?
In Al2Cl6, there are six Al-Cl bonds, and all six bonds are of the same length due to the symmetrical nature of the molecule. The incorrect statement is that there are four Al-Cl bonds of the same length and two of different lengths.
Carbon dioxide is a gas but silica is a solid because:
If that is true, and elements in the same period have similar properties because they have the same number of valence electrons, then why is SiO2 a solid and CO2 a gas? Surely a difference in mass by a factor of 2.5 can't be that big a deal.
Is it because of a van der Waals force difference, because silicon has extra electrons which result in compounds being formed from it being more symmetrical than those formed from carbon?
Ready to ace NEET?
Free access · No credit card required
Yes. You can attempt every Chemistry question on this page for free without logging in, and check the correct answer with a detailed explanation instantly.
No account is required to attempt questions and view answers. A free account adds bookmarks, personal notes, and progress tracking.
The bank mixes NEET previous year questions (PYQs) with practice questions, each tagged with its exam appearances where applicable.