Answer:
C + O2 → CO2
Explanation:
C + O2 → CO ----------------- (1)
from equ (1) on reactant side, C has 1 mole, O has 2 moles
from equ (1) on product side, C has 1 mole, O has 1 mole
Thus, to balance the equation, O should have 2 moles
C + O2 → CO2
Answer : The final temperature of the copper is, 
Solution :
Formula used :

where,
Q = heat gained = 299 cal
m = mass of copper = 52 g
c = specific heat of copper =
= final temperature = ?
= initial temperature = 
Now put all the given values in the above formula, we get the final temperature of copper.


Therefore, the final temperature of the copper is, 
Answer:
Answers are explained below
Explanation:
(a)
Oxidation number of iron :
FeO = +2
Fe2O3= +3
Fe3O4 = +2 and +3 since Fe3O4 is the mixture of FeO and Fe2O3.
(b) FeO + CO ----> Fe (s) + CO2
(c) In a pure iron metallic bond is exist between the particles of Fe. But in the form of ore metals forms ionic bond with the non-metals.
Hence the properties vary.
Yes carbon steel has greater strength than that of pure iron but retains the property of iron because no chemical reaction occurs between carbon and iron.
d)
Mixing of carbon in iron is a type of physical change since there is no chemical reactions occur between the carbon and iron. Carbon atoms diffuses in the place between the iron atoms.
(f) One of the property of non-metals are brittleness. It is non ductile .
So when the percentage of carbon increases its atoms also occupying more and more free places.
And increasing the brittleness. So the iron becomes less ductile.
e)
The name come from the German 'Bisemutum' a corruption of 'Weisse Masse' meaning white mass.
The answer is E.
Chemoautotrophs are organisms that use inorganic <span>compounds as an energy source and CO2 as a carbon source. The organisms live in </span>hostile environments like dark depths of the sea. Inorganic energy sources that they use are mostly hydrogen sulfide, elemental sulfur, ferrous iron, molecular hydrogen, and ammonia.