SAT (Stage-2) Mock Test - 35

The octet rule observe that the atoms of main-group elements tend to combine in such a way that each atom has eight electrons in its valence shell, giving it the same electron configuration as a noble gas.

Sulphur dioxide (SO₂) contains one atom of sulphur and two atoms of oxygen.

Mass of one sulphur atom = 2x g

Mass of one oxygen atom = x g

Thus, the ratio of the masses of sulphur and oxygen in sulphur dioxide is 1 : 1.

According to Boyle's Law, at constant temperature, the volume of a given mass of gas is inversely proportional to its pressure. Hence, if the pressure is increased in the cylinder, the volume decreases.

On heating, iron and sulphur react to form a new substance.
Iron + sulphur → Iron sulphide
Iron sulphide does not show the properties of iron or sulphur and is not magnetic.
Hence, nothing will stick to the magnet.

When alpha particles are sent through a thin metal foil, only one out of ten thousands of them is rebounded. This observation leads to the conclusion that positively charged particles are concentrated at the centre of the atom.

The limitation of Newlands law of octaves:

In order to fit elements into his table, Newlands adjusted two elements in the same slot, but also kept some unlike elements under the same slot. Cobalt and nickel are in the same slot and are placed in the same column as fluorine, chlorine and bromine, which have very different properties. Thus, Newlands law of octaves worked well with lighter elements only.

The chemical formula of water molecule is H₂O in which oxygen has 6 valence electrons and each hydrogen has one. Hydrogen tends to get duplet configuration which is for next noble gas; Helium. Hence, each hydrogen can form one bond to set stable configuration and oxygen requires two electrons to get noble gas configuration for stability. Therefore, the correct electron dot structure of H₂O is:

The compound given in option (1) is a saturated compound. Rest all the compounds are unsaturated. Thus, option (1) is the odd one out.

KMnO₄ is a strong oxidising agent and oxidises the alkenes to form alcohols.

Hence, the violet colour of KMNO₄ solution is discharged in test tube 'B' as ethene gets oxidised.

There is no colour change observed in test tube 'A'.

Copper does not form hydrogen on reaction with nitric acid as nitric acid is a strong oxidising agent. It oxidises copper to Cu²⁺ ions and the nitric acid is reduced to nitrogen dioxide, a poisonous brown gas with an irritating odour.

Cu (s) + 4HNO₃ (aq) → Cu(NO₃)₂ (aq) + 2NO₂ (g) + 2H₂O (l)

The given reaction is a redox reaction in which copper is getting reduced and sulphur is getting oxidised.

The outer layer of the trunk of tree has dead cells or cork cells, so nothing would happen if a metal plate is nailed on the trunk of the tree.

In anaphase stage, chromatids start moving towards the opposite poles, while the chromosomes are drawn to each side of the cell. The non-kinetochore spindle fibres push against each other, in a ratcheting action, that stretches the cell into an oval.

Presence of nervous system in the form of dorsal nerve cord is one of the fundamental characters of chordates. The dorsal nerve cord is later modified in vertebrates into the central nervous system which is composed of the brain and the spinal cord. Dorsal nerve cord is mainly found in subphylum Vertebrata.

The medulla oblongata is the primary respiratory control center. Its main function is to send signals to the muscles that control respiration to cause breathing to occur. There are two regions in the medulla that control respiration: The ventral respiratory group stimulates expiratory movements.