JEE Mains · Chemistry · STD 11 - 3. Classification of elements and periodicity in properties

Given below are two statements :
Statement (I) : According to the Law of Octaves, the elements were arranged in the increasing order of their atomic number.
Statement (II) : Meyer observed a periodically repeated pattern upon plotting physical properties of certain elements against their respective atomic numbers.
In the light of the above statements, choose the correct answer from the options given below :

A Both Statement (I) and Statement (II) are false.
B Both Statement (I) and Statement (II) are true.
C Statement (I) is false but Statement (II) is true.
D Statement (I) is true but Statement (II) is false.

Verified Solution

Answer & Solution

Correct Answer

(A) Both Statement (I) and Statement (II) are false.

Step-by-step Solution

Detailed explanation

Law of octaves was arranged in the increasing order of their atomic weight. Lothar Meyer plotted the physical properties such as atomic volume, melting point and boiling point against atomic weight.

Apply the relevant identity from the chapter and substitute the values established in the previous step, keeping the original constraint in view.

Use the simplified expression to isolate the unknown, then plug the result back into the question setup to confirm the working is internally consistent.

Cross-check against a boundary or limiting case. Both the dimensional balance and the qualitative behaviour at the extreme should agree with the candidate answer.

Combine the steps above to identify the correct option. The remaining choices each fail at least one of the consistency, dimensional, or boundary checks.

Same subject

Explore more questions on app

From JEE Mains

Match List \(I\) with List \(II\) :-

सूची-\(I\) coordination compounds	सूची-\(II\) numbar of unpaired electrons
\(A\) \(\left[ Cr ( CN )_6\right]^{3-}\)	\(I\) \(0\)
\(B\) \(\left[ Fe \left( H _2 O \right)_6\right]^{2+}\)	\(II\) \(3\)
\(C\) \(\left[ Co \left( NH _3\right)_6\right]^{3+}\)	\(III\) \(2\)
\(D\) \(\left[ Ni \left( NH _3\right)_6\right]^{2+}\)	\(IV\) \(4\)

Choose the correct answer from the options given below :-

JEE Mains 2023 Medium

Given below are two statements: one is labelled as Assertion \(A\) and the other is labelled as Reason \(R\). Assertion \(A :\) Dipole-dipole interactions are the only non-covalent interactions, resulting in hydrogen bond formation. Reason \(R\) : Fluorine is the most electronegative element and hydrogen bonds in \(HF\) are symmetrical. In the light of the above statements, choose the most appropriate answer from the options given below.

JEE Mains 2021 Easy

Match List \(I\) with List \(II.\)

List \(I\)	List \(II\)
\((a)\) Rectifier	\((i)\) Used either for stepping up or stepping down the \(a.c.\) voltage
\((b)\) Stabilizer	\((ii)\) Used to convert \(a.c.\) voltage into \(d.c.\) voltage
\((c)\) Transformer	\((iii)\) Used to remove any ripple in the rectified output voltage
\((d)\) Filter	\((iv)\) Used for constant output voltage even when the input voltage or load current change

Choose the correct answer from the options given below:

JEE Mains 2021 Medium

A body rotating with an angular speed of \(600\, {rpm}\) is uniformly accelerated to \(1800 \,{rpm}\) in \(10\; sec\). The number of rotations made in the process is ..... .

JEE Mains 2021 Medium

Explore more questions on app