Strontium is a reactive metal that can be dissolved easily in hydrochloric acid. Let us see some of the interesting features of the chemical reaction in this article.
In the reaction HCl + Sr more reactive metal displaces less reactive ones. Hydrochloric acid (HCl) is a strong inorganic acid that gives hydronium ions (H3O+) aqueous medium. Strontium (Sr) is a highly reactive alkaline earth soft silvery-white metal.
In this article, we will learn how metals react with acid, what the products form and how to balance the chemical equation.
What is the product of HCl and Sr?
HCl + Sr gives strontium dichloride (SrCl2), and hydrogen gas(H2).
Sr + HCl = SrCl2 + H2
What type of reaction is HCl + Sr?
HCl + Sr follows displacement reaction because Sr is more reactive than hydrogen, thus displacing hydrogen from HCl, giving hydrogen gas.
How to balance HCl + Sr?
The chemical reaction for HCl + Sr will be balanced by following steps as per Law of Conservation of Mass.
- First count the number of atoms present in the reactant and product
- HCl + Sr = SrCl2 + H2
| Atom | Reactant | Product |
|---|---|---|
| H | 1 | 2 |
| Cl | 1 | 2 |
| Sr | 1 | 1 |
- The above equation is not balanced as no hydrogen and the chlorine atom is 1 in the reactant and 2 in the product.
- Multiply 2 with HCl, and then again check for the atoms in both reactant and product.
- 2HCl + Sr = SrCl2 + H2
- Finally, we get a balanced chemical equation in which the stoichiometry for HCl, Sr, SrCl2, and H2 comes out to be 2, 1, 1, 1, respectively.
- 2HCl + Sr = SrCl2 + H2
HCl + Sr titration
HCl and Sr cannot be titrated because strontium is a reactive metal which reacts with hydrochloric acid to give the most combustible Hydrogen gas.
HCl + Sr net ionic equation
The net ionic equation of HCl + Sr is:
2H+(aq) + 2Cl–(aq) + Sr(s) = Sr2+(aq) + 2Cl–(aq) + H2(g)
Following steps are used to derive the net ionic equation :
- First, write the balanced chemical equation and represent physical states of each reactant and product.
- 2HCl(aq) + Sr(s) = SrCl2(aq) + H2(g)
- Now, strong acids, bases and salts will dissociate into ions, but pure substances and molecules like Sr and H2 will not dissociate.
- 2H+(aq) + 2Cl–(aq) + Sr(s) = Sr2+(aq) + 2Cl–(aq) + H2(g)
HCl + Sr conjugate pairs
- The mixture of HCl + Sr forms the conjugate acid-base pairs because HCl is a Bronsted acid which tends to donate a proton (H+) and Cl– accept a proton (H+).
- The conjugate base of HCl is Cl–.
HCl and Sr intermolecular forces
- HCl + Sr show the dipole-induced-dipole intermolecular force of attraction.
- HCl molecule has permanent dipole moments, due to the electronegativity difference between H and Cl.
HCl + Sr reaction enthalpy
The enthalpy of the HCl + Sr reaction is -2420.4 kJmol-1.
| S.No. | Chemical Compound | Standard enthalpy of formation (Hform) (kJmol-1) |
|---|---|---|
| 1 | HCl | -92.3 |
| 2 | Sr | +1777.0 |
| 3 | SrCl2 | -828.0 |
| 4 | H2 | 0 |
Hrxn = HSrCl2 + HH2 – HHCl – HSr
= (-828.0+0.0-1777.0+2*92.3)
= -2420.4 kJmol-1
Is HCl + Sr a buffer solution?
HCl + Sr does not form a buffer solution because hydrochloric is a strong acid which does not form the buffer solution. Also, Sr readily dissolves in HCl to give hydrogen gas.
Is HCl + Sr a complete reaction?
HCl+Sr is a complete reaction because Sr is the reactive metal that displaces the hydrogen atom from HCl, giving salt and H2 gas.
Is HCl + Sr an exothermic or endothermic reaction?
HCl + Sr is an exothermic reaction that can be observed from the standard enthalpy of the reaction which comes out to be -2420.4 kJmol-1.
Is HCl + Sr a redox reaction?
HCl + Sr is a redox reaction because the oxidation state of Sr increases from zero to +2, and the oxidation state of hydrogen decreases from +1 to zero.
Is HCl + Sr a precipitation reaction?
HCl + Sr is not a precipitation reaction because the product SrCl2 does not form a precipitate during the reaction due to its more covalent character.
Is HCl + Sr reversible or irreversible reaction?
The reaction between HCl and Sr is not a reversible because the H2 gas evolves out of the reaction. Thus cannot revert back.
Is HCl + Sr displacement reaction?
HCl + Sr shows a displacement reaction. Sr has more negative reduction potential than H (Zero V). Therefore, Sr displaces hydrogen from hydrochloric acid.
Conclusion
The reaction of hydrochloric acid with Strontium produces Strontium chloride and hydrogen gas. In this reaction both oxidation and reduction occurs simultaneously therefore the reaction is termed as redox reaction. Also, the reaction is an example of dispalcement reaction.
Hello, I am Dr. Vikas Khatri. I completed my PhD from the Department of Chemistry, Indian Institute of Technology Delhi. I have several research articles published in International Journals. I have more than 10 years of experience working as a chemistry professional. Please go through my LinkedIn profile for further details:
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