chemical reactions- help (1 Viewer)

[jjuunnee]

Just need an explanation for these two chemical reactions and why the reactants created the products (btw equations aren't balanced)

Ca + H₂O --> Ca(OH)₂ + H₂

CaCO₃ + HCl --> CaCl₂ + CO₂ + H₂O

 

[ProdigyInspired]

a)Ca + 2H₂O --> Ca(OH)₂ + H₂

metal + water = metal oxide/hydroxide + hydrogen (hydroxide in this case)
water is oxidising agent i.e. it gets reduced, Ca is oxidised and gains OH i.e. becomes basic. OH has 2 because Ca ion has 2+, and OH is 1-

b)CaCO₃ + 2HCl --> CaCl₂ + CO₂ + H₂O

carbonate + acid = salt + carbon dioxide + water

Cl^1- displaces CO₃^2- to form CaCl₂

H⁺ combines with the CO₃^2- to form H₂CO₃
H₂CO₃ decomposes to form water + co2
(edit: this is because hydrogen carbonate i.e. carbonic acid is a weak acid, i.e. it decomposes/disassociates)

 

[ProdigyInspired]

I just realised you're 2 years away from HSC

don't worry about oxidation/reduction right now

basically remember the carbonate + acid & metal + water results, and learn to balance equations
Pretty much when I say displace it means they swap around.
Keep in mind that alot of equations occur just by swapping positions with each other.

The top right represent the electrons they need to lose/gain to get a full outer shell (remember octet rule 2,8,8 ...)

edit: if you want to learn more about reduction/oxidation i.e. redox reactions
first just keep in mind Oxidation Is Loss of electrons, and Reduction Is Gain of electrons.
i.e. O.I.L.R.I.G