not be changed to balance an equationSubscripts are part of the chemical formula for reactants or products and can
Changing a subscript changes the substance represented by the formula
H2(g) +C2H4(g)→C2H6(g)
H-H +H2C =CH2→H3C-Ch3
2C -H bonds and one C-C bond are formed while enthalpy change (dH) of the reaction,
H-H: 432kJ/mol
C=C: 614kJ/mol
C-C: 413 kJ/mol
C-C: 347 kJ/mol
dH is equal to sum of the energies released during the formation of new bonds or negative sign, and sum of energies required to break old bonds or positive sign.
The bond which breaks energy is positive.
432+614 =1046kJ/mol
Formation of bond energy is negative
2(413) + 347 = 1173 kJ/mol
dH reaction is -1173 + 1046 =-127kJ/mol
Once you balance the enquation you "switch partners" of the element (negative charge to positive charge)
The minimum volume of 0.2M sodium sulfide that will precipitate out aluminum from 50.0 mL, 0.25 M aluminum nitrate would be 0.094 L or 94 mL
<h3>Stoichiometric calculation</h3>
From the equation of the reaction:

Mole ratio of Na2S and Al(NO3)3 = 3:2
Mole of 50.0 mL, 0.25 M Al(NO3)3 = 50/1000 x 0.25
= 0.0125 mole
Equivalent mole of Na2S = 3/2 x 0.0125
= 0.0188 mole
Volume of 0.2M, 0.0188 mole Na2S = 0.0188/0.2
= 0.094 L or 94 mL
More on stoichiometric calculations can be found here: brainly.com/question/8062886
The question is incomplete, here is the complete question:
Silicon reacts with carbon dioxide to form silicon carbide and silicon dioxide. Write the balanced chemical equation.
<u>Answer:</u> The balanced chemical equation is written below.
<u>Explanation:</u>
Every balanced chemical equation follows law of conservation of mass.
A balanced chemical equation is defined as the equation in which total number of individual atoms on the reactant side is equal to the total number of individual atoms on product side.
The balanced chemical equation for the reaction of silicon and carbon dioxide follows:

By Stoichiometry of the reaction:
2 moles of silicon reacts with 1 mole of carbon dioxide gas to produce 1 mole of silicon carbide and 1 mole of silicon dioxide
Hence, the balanced chemical equation is written above.