The three steps involve;
Step 1: Separation/expansion of the solute particles
Step 2: Separation/expansion of the solvent particles
Step 3; Combining the solute and solvent particles
The first two steps are usually endothermic. Step 3, nonetheless, can be either exothermic or endothermic and is significant in determining whether the dissolving process will be endothermic or exothermic.
X(OH)₂ + 2HCl = XCl₂ + 2H₂O
n{X(OH)₂}=m{X(OH)₂}/M{X(OH)₂}
n(HCl)=c(HCl)v(HCl)
n{X(OH)₂}=n(HCl)/2
m{X(OH)₂}/M{X(OH)₂}=c(HCl)v(HCl)/2
M{X(OH)₂}=2m{X(OH)₂}/{c(HCl)v(HCl)}
M{X(OH)₂}=2*8.65/{2.50*56.9*10⁻³}=121.6 g/mol
M(OH)=17.0 g/mol
M(X)=121.6-17.0*2=87.6 g/mol ⇒ X=Sr, strontium
Sr(OH)₂ + 2HCl = SrCl₂ + 2H₂O
No, it can be Igneous rock as well