Answer:
Explanation:
13 ) symbol of enthalpy change = Δ H .
14 ) enthalpy change is nothing but heat absorbed or evolved .
During fusion enthalpy change
Δ H .= m Lf , m is mass and Ls is latent heat of fusion
During evaporation, enthalpy change
Δ H .= m Lv , m is mass and Lv is latent heat of evaporation
during temperature rise , enthalpy change
Δ H = m c Δ T
In case of gas , enthalpy change can be calculated by the following relation
Δ H = Δ E + W , Δ E is change in internal energy , W is work done by gas.
15 ) When enthalpy change is negative , that means heat is released to the environment .So reaction is called exothermic .
when heat is absorbed enthalpy change is positive . Reaction is endothermic.
The answer is <span>Plastics, Medicine, Clothing, Paper. </span>Coal is used in the making of Plastics, Medicine, Clothing, Paper. Some important users of coal include alumina refineries, paper manufacturers, and the chemical and pharmaceutical industries. Thousands of different products have coal or coal by-products as components: soap, aspirins, solvents, dyes, plastics and fibres, such as rayon and nylon.
It depends if it occurs naturally it has oxidation number of 0
but when it react with other element it has an oxidation number of -1
The answer is 2
Hope this helped ??
