Question

Silver carbonate is a white powder. When heated in a dry test tube, it forms solid grey silver and colourless gases namely, carbon dioxide and oxygen ${\mathrm{Ag}}_2{\mathrm{CO}}_3\stackrel{∆}{\to }\mathrm{Ag}+{\mathrm{CO}}_2+{\mathrm{O}}_2$. What conclusions can you draw regarding four substances: silver carbonate, silver, carbon dioxide, oxygen

Answer 1

Given,

$\underset{(\mathrm{Silver}\mathrm{carbonate})}{2{\mathrm{Ag}}_2{\mathrm{CO}}_3}\stackrel{∆}{\to }\underset{\left(\mathrm{Silver}\right)}{4\mathrm{Ag}}+\underset{(\mathrm{Carbon}\mathrm{dioxide})}{2{\mathrm{CO}}_2}+\underset{\left(\mathrm{Oxygen}\right)}{{\mathrm{O}}_2}$

Silver carbonate $\left({\mathrm{Ag}}_2{\mathrm{CO}}_3\right)$ undergoes decomposition to form Silver $\left(\mathrm{Ag}\right)$, Carbon dioxide $\left({\mathrm{CO}}_2\right)$ and Oxygen $\left({\mathrm{O}}_2\right)$

The following conclusions can be drawn about the substances in the reaction:

• Silver carbonate: It is a compound as it comprises three elements i.e.; Silver $\left(\mathrm{Ag}\right)$, Carbon $\left(\mathrm{C}\right)$ and Oxygen $\left(\mathrm{O}\right)$ combined chemically in a definite ratio of 2:1:3.
• Silver: It is an element as it consists of only Silver atoms which cannot be broken down into simpler substances.
• Carbon dioxide: It is a compound of two elements i.e.; Carbon $\left(\mathrm{C}\right)$ and Oxygen $\left(\mathrm{O}\right)$ combined in a 1:2 ratio.
• Oxygen: It is an element as it consists of only Oxygen $\left({\mathrm{O}}_2\right)$ molecules

Element: An element is a pure substance that cannot be split into simpler substances.

• Example: Hydrogen $\left({\mathrm{H}}_2\right)$, Copper $\left(\mathrm{Cu}\right)$ etc.

Compound: A compound is a pure substance in which elements combine chemically in a fixed composition to give a compound.

• They can be broken down into elements that make up the compound by using chemical or electrochemical methods.
• The properties of the compound are entirely different from the elements from which it is formed.
• Example: Water $\left({\mathrm{H}}_2\mathrm{O}\right)$, Common salt i.e.; Sodium chloride $\left(\mathrm{NaCl}\right)$

Mixture: When two or more substances (elements or compounds or an element and compound) are mixed in any proportion.

• The components of a mixture can be separated by physical methods of separation.
• Example: A mixture of Sand and Iron $\left(\mathrm{Fe}\right)$ can be separated by the use of a magnet (physical process) where Iron gets attracted to the magnet leaving behind the sand.