Balance this equation: Zn + HCl ZnCl₂ + H₂

Question

Balance this equation: Zn + HCl   ZnCl₂ + H₂?  
A. Zn + 2HCl   ZnCl₂ + H₂  
B. . Zn + HCl   2ZnCl₂ + H₂  
C. 2Zn + HCl   2ZnCl₂ + H₂  
D. Zn + 4HCl   ZnCl₂ + H₂

Accepted Answer

Correct Answer: (A)Zn + 2HCl   ZnCl₂ + H₂. 
Rationale: The balanced equation is Zn + 2HCl → ZnCl₂ + H₂.Balancing a chemical equation requires that the number of each type of atom be the same on both sides of the equation, in accordance with the law of conservation of mass. In this reaction, zinc reacts with hydrochloric acid to produce zinc chloride and hydrogen gas. Careful counting of zinc (Zn), hydrogen (H), and chlorine (Cl) atoms on both sides shows that two molecules of HCl are needed to balance the atoms correctly.A. Zn + 2HCl → ZnCl₂ + H₂This option is correct. On the left side, there is one zinc atom, two hydrogen atoms, and two chlorine atoms (from 2HCl). On the right side, there is one zinc atom in ZnCl₂, two chlorine atoms in ZnCl₂, and two hydrogen atoms combined to form H₂ gas. Each element has the same number of atoms on both sides of the equation, making this a properly balanced chemical equation.B. Zn + HCl → 2ZnCl₂ + H₂On the right side, the coefficient 2 in front of ZnCl₂ means there are two zinc atoms and four chlorine atoms. However, on the left side there is only one zinc atom and one chlorine atom from a single HCl molecule. This creates an imbalance in both zinc and chlorine atoms.C. 2Zn + HCl → 2ZnCl₂ + H₂Although the number of zinc atoms appears balanced (two on each side), the hydrogen and chlorine atoms are not. There is only one hydrogen atom and one chlorine atom on the left side from HCl, but there are four chlorine atoms on the right side in 2ZnCl₂ and two hydrogen atoms forming H₂. The coefficients do not properly balance all elements.D. Zn + 4HCl → ZnCl₂ + H₂On the left side, four HCl molecules provide four hydrogen atoms and four chlorine atoms. On the right side, ZnCl₂ contains only two chlorine atoms, and H₂ contains only two hydrogen atoms. This results in excess hydrogen and chlorine atoms on the left side, so the equation is not balanced.ConclusionA balanced chemical equation must have equal numbers of each type of atom on both sides. Only the equation Zn + 2HCl → ZnCl₂ + H₂ satisfies this requirement by balancing zinc, hydrogen, and chlorine atoms correctly while using the smallest whole-number coefficients.

Balance this equation: Zn + HCl ZnCl₂ + H₂

A
Zn + 2HCl ZnCl₂ + H₂

B
. Zn + HCl 2ZnCl₂ + H₂

C
2Zn + HCl 2ZnCl₂ + H₂

D
Zn + 4HCl ZnCl₂ + H₂

The balanced equation is Zn + 2HCl → ZnCl₂ + H₂.

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Balance this equation: Zn + HCl ZnCl₂ + H₂

A Zn + 2HCl ZnCl₂ + H₂ B . Zn + HCl 2ZnCl₂ + H₂ C 2Zn + HCl 2ZnCl₂ + H₂ D Zn + 4HCl ZnCl₂ + H₂

The balanced equation is Zn + 2HCl → ZnCl₂ + H₂.

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Mini Quiz

Related Questions

A
Zn + 2HCl ZnCl₂ + H₂

B
. Zn + HCl 2ZnCl₂ + H₂

C
2Zn + HCl 2ZnCl₂ + H₂

D
Zn + 4HCl ZnCl₂ + H₂