Tag: separation of substances

Air is a homogeneous mixture. However, the Earth's atmosphere as a whole is a heterogeneous mixture. Alloys are made when two or more metals are mixed together. They usually are homogeneous mixtures. Examples include brass, bronze, steel, and sterling silver.

When two liquids do not mix, they form two separate layers and are known as immiscible liquids. These two liquids can be separated by using a separating funnel. It will separate the immiscible liquids into two distinct layers depending on their densities. The heavier liquid forms the lower layer while the lighter one forms the upper layer. Kerosene has lower density than water and hence forms the upper layer.

A mixture is a material system made up of two or more different substances which are mixed but are not combined chemically. A mixture refers to the physical combination of two or more substances on which the identities are retained and are mixed in the form of solutions, suspensions, and colloids.

Water and methane are both made up of two different elements. Water is made up of oxygen and hydrogen whereas methane consists of carbon and hydrogen. Compounds are substances that contain atoms of at least two elements chemically combined. Hence, water and methane are compounds.

Smog is a mixture of smoke and fog. There is no chemical combination and properties of smog are dependent on the properties of its constituent element.

A mixture is composed of two or more pure substances and a mixture always shows the properties of their constituents.

All are the examples of separation of substances. 

Distilled water is the pure form of water with no impurities present in it;

Mixtures can be obtained by a combination of elements and compounds. Thus when they are separated, it can give both elements and compounds, depending upon the constituents of a mixture.
Example: Air is the mixture of various gases. It on separation gives oxygen, nitrogen, carbon dioxide, etc. 

$BaCl _2+H _2S\longrightarrow BaS+2HCl$
                                  $1.69$ $g$
For $1$ $mole$ of $H _2S$ produce $1$ $mole$ of $BaS$
So, $1$ $mole$ $H _2S\longrightarrow 1$ $mole$ $BaS$
            $34$ $g$                      $169$ $g$
                      $(x)\longleftarrow 1.69$ $g$
$\implies x=\cfrac {1.69\times 34}{169}=0.34$ $g$
Amount of $H _2S$ needed $=0.34$ $g$