15 Facts on HCl + Zn(NO3)2: What, How To Balance & FAQs

Zn(NO3)2 is a strong acid and weak base salt that can be reacted with strong hydrochloric acid. Let us see the mechanism behind this reaction.

Zinc nitrate is salt made by the reaction between zinc hydroxide and nitric acid, so it is an acidic salt. It can be ionized in a certain pH at Zn2+ and nitrate anion. The reaction between hydrochloric acid and Zinc nitrate does not require any catalyst, the reactivity of HCl and nitrate ion can forward the reaction.

To standardize the strength of HCl or maybe estimate the nitrate we can perform this reaction between HCl and Zn(NO3)2. In this article, we will learn more about reactions like enthalpy, redox reaction, intermolecular force, conjugate pairs, etc with an explanation in the following part of the article.

1. What is the product of HCl and Zn(NO3)2?

Zinc chloride along with nitric acid is formed when HCl and Zn(NO3)2 are subject to reaction but nitric acid can also be dissociated to its respective conjugate ions.

Product of The reaction Between
HCl and Zn(NO3)2

2. What type of reaction is HCl + Zn(NO3)2?

Besides the Acid-base reaction between HCl + Zn(NO3)2 there are also redox reactions, displacement reactions, and also precipitation reactions that occur at certain pH. The former is strongly acidic but the latter is weakly basic so, a buffer reaction is also observed.

3. How to balance HCl + Zn(NO3)2?

HCl + Zn(NO3)2 = ZnCl2 + HNO3 this reaction is not balanced yet because the L.H.S of the reaction is not equal to the R.H.S., so we have to balance the equation in a few steps,

Step 1 – Labelling all the reactants and products by the required number of alphabets

We labeled all the molecules in the part of the reactant as well as the product side by A, B, C, and D as there is a total of four molecules present unbalanced form. Now the reaction reduces to,        

 A HCl + B Zn(NO3)2 = C ZnCl2 + D HNO3

Step 2 – Equating all the Coefficients for all the same type of elements by rearranging them

Comparing all the same elements by their stoichiometric proportion and coefficients in this reaction we get,

H = A = D, Cl = A = 2C, Zn = B = C, NO3 = 2B = D

Step 3 – Using Gaussian elimination to determine the coefficient values

Using the Gaussian elimination and equating all the equations we get,

A = 2, B = 1, C = 1, D = 2

Step 4- now write the whole equation in the balanced form

The overall balanced equation will be,

2HCl + Zn(NO3)2 =  ZnCl2 +  2HNO3

4. HCl + Zn(NO3)2 titration

To estimate the quantity of nitrate and strength of HCl we can perform a titration between Zn(NO3)2 and HCl in the following way,

Apparatus used

We need a burette, conical flask, burette holder, volumetric flask, and beakers for this titration.

Titre and titrant

HCl versus Zn(NO3)2, HCl acts as titrant which is taken in the burette and the molecule to be analyzed is Zn(NO­3)2 which is taken in a conical flask.


The whole titration is done in an acidic medium or acidic pH so the best suitable indicator will be phenolphthalein which gives perfect results for this titration at given pH.


The burette was filled with standardized HCl and Zn(NO3)2 was taken in a conical flask along with the respective indicator. Then the titration was started by adding HCl dropwise to the conical flask and the flask was shaking constantly. After a certain time when the endpoint arrived and indicator changes its color.

We repeat the titration several times for better results and then we estimate the quantity of nitrate and strength of HCl by the formula V1S1 = V2S2.

5. HCl+ Zn(NO3)2 net ionic equation

The net several ionic forms are H+, along with Cl for reaction HCl + Zn(NO3)2 are Zn2+ and NO3 are the main ions formed during the course of the reaction between HCl and Zn(NO3)2.

2H+ + 2Cl + Zn2+ + 2NO3 = Zn2+ + 2Cl + 2H+ + 2NO3

6. HCl+ Zn(NO3)2 conjugate pairs

The conjugate pairs of the reaction between HCl+ Zn(NO3)2 are listed below –

  • Conjugate pair of HCl = Cl
  • Conjugate pair of Zn(HNO3 )2= NO3

7. HCl and Zn(NO3)2 intermolecular forces

The ionic and electrostatic forces are present in HCl as also dipole interaction and for the Zn(NO3)2. There are coulombic forces along with covalent interaction present with the molecule. Some H-bonding present in HNO3 and for ZnCl2 there is ionic interaction along with van der waal’s interaction present.

MoleculeActing force
van der waal’s,
Zn(NO3)2Coulombic ionic,
van der waal’s
ZnCl2Ionic, Strong
HNO3Ionic, Strong
Intermolecular Forces

8. HCl + Zn(NO3)2 reaction enthalpy

The reaction enthalpy for the reaction between HCl + Zn(NO3)2 is, +1662.34 KJ/mol which can be obtained by the formula enthalpy of products – enthalpy of reactants, and here the change in enthalpy is negative.

Reaction Enthalpy

9. Is HCl + Zn(NO3)2 a buffer solution?

The reaction between HCl + Zn(NO3)2 gives a buffer solution of ZnCl2 and HNO3 which can control the pH of the solution as it has both acidic as well as basic characteristics at certain pH.

10. Is HCl + Zn(NO3)2  a complete reaction?

The reaction of HCl + Zn(NO3)2 is complete reaction which gives two complete products ZnCl2 and HNO3 which indicates that reactants are utilized properly and ends with two complete products.

11. Is HCl + Zn(NO3)2 an exothermic or endothermic reaction?

The change of enthalpy for the reaction of HCl + Zn(NO3)2 indicates it is an endothermic process based on thermodynamics because the enthalpy for the reaction came positive. On the other hand, the reactant absorbed heat in the course of the reaction or we can say δH = HProducts-Hreactans > 0.

12. Is HCl + Zn(NO3)2 a redox reaction?

The reaction HCl+ Zn(NO3)2 is a redox reaction where the oxidation number of several elements is changed like Cl gets reduced whereas Zn and NO3 get oxidized when HCl and Zn(NO3)2 get reacted together.

Redox Schematic of Reaction
Between HCl and Zn(NO3)2

13. Is HCl + Zn(NO3)2 a precipitation reaction

In the above reaction between HCl + Zn(NO3)2 is a precipitation reaction where ZnCl2 is precipitated at the acidic pH. The optimum pH for the precipitation of ZnCl2 is 6.6 and the total titration was done in an acidic medium so ZnCl2 precipitated in this reaction.

14. Is HCl + Zn(NO3)2 reversible or irreversible reaction?

The reaction between HCl + Zn(NO3)2 is irreversible in nature because that reaction proceeds only forward direction at that certain pH.

15. Is HCl + Zn(NO3)2 displacement reaction?

It is an example of a displacement reaction between HCl + Zn(NO3)2 because Zn and Cl are displaced and get attached to the nitrate of the product.


To estimate the quantity of NO3 we can use the titration between Zn(NO3)2 and HCl because Zn(NO3)2 is the raw form where NO3 is stored. By this reaction, we also estimate the strength of HCl as well. The reaction does not require any catalyst or temperature because it is an endothermic reaction.

Biswarup Chandra Dey

Hi......I am Biswarup Chandra Dey, I have completed my Master's in Chemistry from the Central University of Punjab. My area of specialization is Inorganic Chemistry. Chemistry is not all about reading line by line and memorizing, it is a concept to understand in an easy way and here I am sharing with you the concept about chemistry which I learn because knowledge is worth to share it.

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