Question

but -2-yne+ h2+Na/Los NH3 ----- complete the eymquation

Answer 1

In general before one attempts to balance the masses in a chemical reaction is necessary to determine first if there is a change of oxidation state  (* ) from the reactants to the product of the reaction..If there is a change the total units of oxidation-reduction must be first balanced before balancing the mass.In this case :   N2 + H2 = NH3   N2 is in the 0 oxidation state ( uncombined) and as a product in NH3is in the -3 oxidation state ( because it is combined with 3H+) this means  there is a reduction of 3 units per N atom  and a total of 6 for the 2 atoms reacting.. now H is in the 0 oxidation state also and is oxidized to the +1 state in the product NH3 and since there are 2 of them the total oxidation units are2.  A reaction requires the number of oxidation units to be equal to the reduction units. We can obtain this by using 3 molecules of H . If we use 3H2,the equation will be balanced in redox units.                N2+ 3H2  = NH3 Now the mass balance.There are 2 N on the left and only one on the right. a coefficient of 2 for NH3 will satisfy the mass requirements  ( 2N,left; 2N right; 6H left; 6H right )                                     N2 + 3H2  = 2 NH3                                    _________________________________ (*) the oxidation state of an atom is the number of valence electrons shared or exchanged to produce the chemical bond between to different atoms. Uncombined atoms  or atoms of the same elements combined to form a molecule are considered to be in the 0 oxidation state.  A few examples for calculating the state of oxidation:           1.  state of oxidation of Cl in   KCl .Potassium is a metal ( electropositive ) and monovalent .since Cl is combined with one K it most behave as monovalent negative , hence Cl is in the -1 oxidation state          2.    state of oxidation of Cl in HClO4Cl is bound to 4O. Since O is electronegative and divalent  (_2} x 4 =-8 and 1H ( 1+ ).one of the negative valence of oxygen is compensated by one positive valence of H and the remaining 7 negative valences must be compensated by Cl.   In this case then Cl is in the +7 oxidation state.          3.  State of oxidation of S in  H2SO4.     S is bound to 4O  ( -8 total negative valences ) and 2 H  ( 2 positive valences ) the 6 free negative valences must be compensated by S .In this compound S is in the +6 oxidation state.     Kind Regards.
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