How do we balance Zn + HNO3 Zn(NO3)2 + NO + H20

3Zn + 8HNO₃⇒ 3Zn(NO₃)₂ + 2NO + 4H₂O

Equalization of chemical reaction equations can be done using variables. Steps in equalizing the reaction equation:  

For gas combustion reaction which is a reaction of hydrocarbons with oxygen produces CO₂ and H₂O (water vapor). can use steps:  

Balancing C atoms, H and the last O atoms

Reaction

Zn + HNO₃⇒ Zn(NO₃)₂ + NO + H₂O

aZn + bHNO₃⇒ Zn(NO₃)₂ + cNO + dH₂O

Zn : left = a, right =1 ⇒a=1

H : left = b, right = 2d⇒ b=2d (eq 1)

N : left = b, right = 2+c⇒b=2+c (eq 2)

O : left = 3b, right = 6+c+d ⇒3b=6+c+d(eq 3)

3(2d)=6+c+d

6d=6+c+d

5d=6+c (eq 4)

3(2+c)=6+c+d

6+3c=6+c+d

2c=d (eq 5)

5(2c)=6+c

10c=6+c

9c=6

c = 2/3

d = 2 x 2/3

d = 4/3

b = 2 x 4/3

b = 8/3

The equation

aZn + bHNO₃⇒ Zn(NO₃)₂ + cNO + dH₂O to

Zn + 8/3HNO₃⇒ Zn(NO₃)₂ + 2/3NO + 4/3H₂O x 3

3Zn + 8HNO₃⇒ 3Zn(NO₃)₂ + 2NO + 4H₂O

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