Question

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

Answer 1

3Zn + 8HNO₃⇒ 3Zn(NO₃)₂ + 2NO + 4H₂O

Further explanation

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

• 1. gives a coefficient on substances involved in the equation of reaction such as a, b, or c etc.  

• 2. make an equation based on the similarity of the number of atoms where the number of atoms = coefficient × index between reactant and product  

• 3. Select the coefficient of the substance with the most complex chemical formula equal to 1  

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

• 1. gives a coefficient

aZn + bHNO₃⇒ Zn(NO₃)₂ + cNO + dH₂O

• 2. make an equation

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)

• From eq 1 and eq 3

3(2d)=6+c+d

6d=6+c+d

5d=6+c (eq 4)

• From eq 2 and eq 3

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

6+3c=6+c+d

2c=d (eq 5)

• From eq 4 and eq 5

5(2c)=6+c

10c=6+c

9c=6

c = 2/3

• input eq 5

d = 2 x 2/3

d = 4/3

• input eq 1

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