Question

The alloy bronze contains copper and tin. This is a:
[A] Homogeneous mixture
[B] Heterogeneous mixture
[C] Solid solution of two immiscible metals
[D] Pure substance.

Answer 1

Hint: An alloy is a mixture of a metal or a non-metal containing one or more other elements. This mixture thus formed is preventive against corrosion. In an alloy, metal along with the other element is completely mixed through heating the base metal and mixing it with other elements and forms a new material with enhanced capabilities than the pure metal.

Complete step by step answer:
Before answering the given question, let us understand what an alloy is.
An alloy is a mixture of metal or nonmetal of one or more than one element. However, the properties of the resulting mixture are quite different from the pure metal used like its strength and hardness. An alloy generally retains all the properties of a metal like conductivity of electricity, its opaque surface, malleability and ductility and lustre.
Alloys are of great use all over the world due to its increased strength and greater longevity. The most common example of alloy is stainless steel which is an alloy of iron and chromium. Chromium prevents the iron from rusting and thus corrosion whereas the normal non-alloy steel is prone to rusting and staining.

Now, let us discuss the given options to answer this question.
Firstly we have a homogenous mixture. We know that a homogeneous mixture is a mixture where the proportion of the components of the mixture is the same throughout the sample. Here, in an alloy as two metals (or non-metals) are mixed and they behave as a one, a new metal thus an alloy is a homogeneous mixture. Therefore, this is the correct answer.
In the next option we have a heterogeneous mixture. We know that the mixture where the proportion of the components of the mixture is not the same throughout the sample is a heterogeneous mixture. An alloy cannot be a heterogeneous mixture. Therefore, this is not the correct answer.
In the third option we have a solid solution of two immiscible metals. As we know in a solid solution one or two solutes are present in a solvent in solid state and it is considered a solution and not a compound. Therefore, this is not the correct answer.
And lastly we have pure substance. As we can see that the alloy here is a mixture of bronze containing copper and tin. Therefore, this is not a pure substance thus this option is incorrect.
We can see from the above discussion that the alloy of bronze containing copper and tin is a homogeneous mixture. So, the correct answer is “Option A”.

Note: An alloy of bronze containing copper forms a layer of copper oxide and is eventually converted into copper carbonate on the surface and thus prevents corrosion of the metal. But in case copper chloride is created, it causes bronze disease which is a chloride corrosion of cuprous materials. Also, the copper based alloys have a lower melting point which allows us to make them at lower temperatures compared to other iron alloys.