Question

For $$4.5g$$ of an alloy of copper and zinc contains $$3.5g$$ of copper. What weight of copper will be there in $$18.9g$$ of the alloy?

Answer 1

Hint: A single element can be regarded as a metal or nonmetal or metalloid. An alloy is a mixture of metals or the metals combined with one or more different elements. It is considered as the combination of different metals. Different combinations of metals form different alloys with different characteristic properties.

Complete answer:
We regard a single element as a metal or nonmetal or metalloid. While we can define an alloy as a mixture of metals or the metals combined with one or more different elements. It is considered as the combination of different metals. Different metals or elements combine in different compositions to produce an alloy of different physical and chemical properties.
Now, if we take the given alloy of copper and zinc, we are given with:
$$4.5g$$ of an alloy of copper and zinc contains $$3.5g$$ of copper.
So, to find out the weight of copper in $$18.9g$$ of alloy, first we will find the weight of copper in $1g$ of alloy.
Therefore, $1g$ of alloy contains $ = \left( {\dfrac{{3.5}}{{4.5}}} \right) \times 1$
$1g$ of alloy contains $0.778g$ of copper.
Now, $$18.9g$$ of the alloy contains $ = 0.778 \times 18.9$
$$18.9g$$ of the alloy contains $14.7g$ copper in it.

Note:
There are many applications of alloys in our day to day life. Alloy of gold and copper is used to make jewellery. Alloy of Aluminium and copper which is known as duralumin is used to make parts of the aircraft. Brass which is an alloy of copper and zinc is used in the manufacture of musical instruments and coins.