Consider the Assertion and Reason given below.
Assertion (A): Ethene polymerized in the presence of Ziegler Natta Catalyst at high temperature and pressure is used to make buckets and dustbins.
Reason (R): High density polymers are closely packed and are chemically inert. Choose the correct answer from the following:

We have to judge the truth values of the Assertion (A) and the Reason (R) and also decide whether the Reason actually explains the Assertion.

First, recall the basic facts about the polymerisation of ethene $$\left(\text{CH}_2 = \text{CH}_2\right)$$.

When ethene is polymerised in the presence of a Ziegler-Natta catalyst, and the reaction is carried out at comparatively high temperature and pressure, the product obtained is called high-density polyethene, commonly abbreviated as $$\text{HDPE}$$. The Ziegler-Natta catalyst system is usually $$\text{TiCl}_4$$ supported on $$\text{Al}(\text{C}_2\text{H}_5)_3$$, and it promotes a stereoregular insertion of ethene units into the growing chain. Because of this stereoregularity the chains are able to pack very closely. Closer packing means:

$$\text{Greater chain-chain attraction} \;\Longrightarrow\; \text{higher crystalline regions} \;\Longrightarrow\; \text{higher density (about }0.94\ \text{g cm}^{-3}\text{)}.$$

The resulting material is rigid, possesses high tensile strength and shows excellent chemical inertness. These properties make it suitable for moulding into articles such as buckets, dustbins, pipes, bottles, toys, etc.

Hence the Assertion “Ethene polymerised in the presence of Ziegler Natta catalyst at high temperature and pressure is used to make buckets and dustbins” is factually correct.

Now consider the Reason. It states: “High-density polymers are closely packed and are chemically inert.” The statement is again correct because high density results from close packing of linear chains; the absence of bulky branching in $$\text{HDPE}$$ leads to strong van der Waals forces, higher crystallinity and, consequently, resistance to chemicals.

We must still decide whether this Reason explains why $$\text{HDPE}$$ can be used for buckets and dustbins. The suitability of a material for such everyday containers depends on rigidity, strength and chemical inertness so that the container can hold water, detergents, household acids or alkalis without degrading. The Reason exactly pinpoints two crucial characteristics—close packing (which gives strength) and chemical inertness—thereby providing the very explanation for the Assertion.

Therefore:

• (A) is true. • (R) is true. • (R) correctly explains (A).

According to the standard pattern for Assertion-Reason questions, this situation corresponds to Option C: “Both (A) and (R) are correct and (R) is the correct explanation of (A).”

Hence, the correct answer is Option C.