15 Facts About HNO3 + Ca: How This Combination Works

Nitric acid is a chemical compound represented by the formula HNO3. Calcium is an alkaline earth metal. Let us discuss various facts related to the reaction of HNO3 + Ca.

Nitric acid is also known as the spirit of niter. Nitric acid is a colorless liquid with a molar mass of 63.012gmol-1. HNO3 melts at -420C and its boiling point is found at 830C. HNO3 is soluble in water. Calcium is a chemical element with atomic number 20.Ca when exposed to air form a dark oxide-nitride layer.

We will talk about various aspects related to the HNO3 + Ca reaction, such as conjugate pair, and type of reaction in this article. 

What is the product of HNO3 and Ca

The product of the reaction between HNO3 + Ca is calcium nitrate(Ca(NO3)2) and hydrogen gas(H2) is evolved.

HNO3 +Ca Ca(NO3)2 + H2

What type of reaction is HNO3 + Ca

The reaction between HNO3 + Ca is a substitution reaction where hydrogen in nitric acid is substituted by calcium to form calcium nitrate.

How to balance HNO3 + Ca

The reaction between HNO3 + Ca is balanced using mentioned steps.

  • If the number of atoms on the reactant and product side is equal then only it is a balanced reaction.
  • Here reaction is HNO3 +Ca Ca(NO3)2 + H2
  • Here on the reactant side one hydrogen, one nitrogen, three oxygen, and one calcium atom are present whereas on the product side two hydrogens, two nitrogen, six oxygen, and one calcium atom are present. This can be tabulated below.
AtomNumber of atoms on Reactant sideNumber of atoms on Product side
H12
N12
O16
Ca11
Table representing the number of atoms on the reactant and product side

                             

  • Above table represents reaction is unbalanced as the number of atoms on both the reactant and product sides is different.
  • We have to balance this reaction by multiplying HNO3 on the reactant side by two.
  • Thus balanced reaction will be 2HNO3 +Ca Ca(NO3)2 + H2

                     

AtomNumber of atoms on Reactant sideNumber of atoms on Product side
H22
N22
O66
Ca11
Table representing the number of atoms on the reactant and product side

Table representing the number of atoms on the reactant and product side

HNO3 + Ca titration

The titration of HNO3 and Ca is not possible as calcium cannot be used in titration as it is a metal.

HNO3 + Ca net ionic equation

The net ionic equation for the reaction HNO3 + Ca is 

Ca(s) +H+ (aq) = Ca2+ (aq) +NO3(aq) +H2 (g).

The net ionic equation can be calculated step by step as below.

  • The soluble ionic compounds dissociate into cations and anions.
  • The ionic equation can be written below.
  • Ca(s) +H+ (aq) + NO3(aq) = Ca2+ (aq) +2NO3(aq) +H2 (g).
  • Spectator ions do not take part in the reaction, so the ions which are common on both the reactant and product side are canceled.
  • So the ions which take part in the reaction can only form a net ionic equation.
  • Net ionic equation finally written as Ca(s) +H+ (aq) = Ca2+ (aq) +NO3(aq) +H2 (g).

HNO3 + Ca conjugate pairs

HNO3+Ca reaction has the following conjugate pairs

  • The conjugate base of HNO3 is NO3.
  • Due to the absence of a proton Ca does not form conjugate pair.

HNO3 and Ca intermolecular forces

The intermolecular forces present in HNO3+Ca are

  • In HNO3 London forces, Hydrogen bonding, and dipole-dipole attraction are present. These forces bind hydrogen ions and nitrite ions to form a molecule.
  • Calcium metal ions show intermolecular forces.

HNO3 + Ca reaction enthalpy

The reaction enthalpy of the HNO3+Ca reaction is +542.1 KJmol-1.

  • The enthalpy of the reaction can be calculated by knowing the enthalpy of the formation of each compound on both the reactant and product side which is tabulated below.
CompoundsEnthalpy of formation (KJ/mol)
HNO3 (aq)-173.1
Ca (s)0
Ca(NO3)2 (aq)369
H2(g)0
  • Change in Enthalpy = (Sum of Enthalpy of formation of Product) – (Sum of Enthalpy of formation of Reactant)

                                            = [(+369) + 0 – (-173.1+0)]

                                            = +542.1 KJmol-1.

Is HNO3 + Ca a buffer solution

HNO3+Ca does not form a buffer solution as HNO3 is a strong acid and Ca is a metal.

Is HNO3 + Ca a complete reaction

The HNO3+Ca reaction is complete as calcium nitrate and hydrogen gas are formed as the stable product of the HNO3+Ca reaction.

Is HNO3 + Ca an exothermic or endothermic reaction

HNO3+Ca is an endothermic reaction as the enthalpy of the reaction is a positive value which is pointed at +542.1 KJmol-1.

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Endothermic graph

                                                     

Is HNO3 + Ca a redox reaction

HNO3+Ca is not a redox reaction as during the HNO3+Ca reaction only the calcium gets oxidized.

Is HNO3 + Ca a precipitation reaction

HNO3+Ca is not a precipitation reaction as no precipitate formed during the reaction, calcium nitrate formed on the product side is soluble in water.

Is HNO3 + Ca reversible or irreversible reaction

HNO3+Ca is an irreversible reaction as the calcium nitrate formed cannot be converted back into the original reactant and hydrogen evolved as a gas during the HNO3+Ca reaction.

Is HNO3 + Ca displacement reaction

HNO3+Ca is a single displacement reaction because the displacement of NO3 from hydrogen takes place by calcium metal.

Conclusion

Nitric acid reacts with Calcium to give calcium nitrate and hydrogen gas is released. Nitric acid is used in the manufacturing of dye, fertilizers, and plastic. HNO3 is used in pure form for the removal of the wart. It is also used in electrochemistry as a doping agent.