Animated Solution for Chemistry - Metallurgy: The incorrect statement is

Welcome to a classic memory-based question from the realm of metallurgy! While it might seem like a simple test of rote memorization, understanding the composition of common alloys is crucial because these materials form the backbone of human civilization. From the Bronze Age to modern aviation, alloys are everywhere. Let's break down each statement and uncover the truth behind these metallic mixtures.

This statement is absolutely correct. Bronze is one of the oldest alloys known to humanity, giving its name to an entire era of history (The Bronze Age). It is primarily composed of Copper ($\text{Cu}$) at around $96\%$, and Tin ($\text{Sn}$) at about $4\%$. The addition of tin makes the copper significantly harder and more durable, which was revolutionary for making tools and weapons in ancient times.

This is also a true statement. Cast iron, which is obtained directly from the blast furnace (often called pig iron before being cast), contains a relatively high amount of carbon (around $3\%$ to $4\%$). This makes it hard but very brittle. To make wrought iron, which is the purest form of commercial iron (containing less than $0.5\%$ carbon), cast iron is heated in a reverberatory furnace lined with haematite. The haematite oxidizes the carbon and other impurities, leaving behind highly malleable and tough wrought iron.

This statement is correct, and it contains a classic chemistry trap! Despite its glamorous name, German silver contains absolutely zero silver. It gets its name purely from its silvery-white, shiny appearance. It is an alloy made of Copper ($\text{Cu}$) at $50\%$, Zinc ($\text{Zn}$) at $30\%$, and Nickel ($\text{Ni}$) at $20\%$. It is widely used in making imitation jewelry, cutlery, and musical instruments.

Here is where we find our error! Brass is a very common and widely used alloy, but it is not made of copper and nickel. Brass is an alloy of Copper ($\text{Cu}$) and Zinc ($\text{Zn}$). Typically, it consists of about $70\%$ copper and $30\%$ zinc. Because it does not contain nickel, this statement is factually incorrect.

Since the question asks us to identify the incorrect statement, we can confidently select option (d). Memorizing the compositions of these fundamental alloys—Brass ($\text{Cu}+\text{Zn}$), Bronze ($\text{Cu}+\text{Sn}$), and German Silver ($\text{Cu}+\text{Zn}+\text{Ni}$)—is a high-yield strategy for competitive exams like JEE and NEET.