Question

A student is given three unlabeled bottles with three possible identities: K2CO3, Ca(NO3)2, and HCl and asked to identify each bottle. The student conducts the following experiment and records the observations as shown. Solutions Mixed Observations A+B A gas is evolved A+C No visible changes Bio A white precipitate is formed 1. Write the net ionic equations resulting from: a) K2CO3 + Ca(NO3)2 b) K2CO3 + HC1 CO² (aq) + 2H+ (aq) - c) Ca(NO3)2 + HC1 CO₂ (g) + He ol 2. Using the net ionic equations, compare the products formed with the observations made, and identify each reagent bottle. A=

Answer 1

Net Ionic Equations of

K₂CO_3(aq) + Ca(NO₃)_2(aq) ----------> 2KNO_3(aq) + CaCO_3(s)

2K⁺ + (CO₃)^2- + Ca²⁺ + 2NO^3- ---------> 2K⁺ + 2NO^3-

^{cancelling the common ions in both sides}

Ca²⁺_(aq) + CO₃^2-_(aq) ---------> CaCO3_(s)

K₂CO_3(aq) + 2HCl _(aq) ----------> H₂O _(l) + CO_2(g) + 2KCl _(aq)

2K⁺_(aq) + CO₃^2-_(aq) + 2H⁺_(aq) + 2Cl^-_(aq) ---------> 2K⁺_(aq) + 2Cl^-_(aq) + H₂O_(l) + CO_2(g)

CO₃^2-_(aq) + 2H⁺_(aq) ---------> H₂O_(l) +CO₂

2HCl _(aq) + Ca(NO₃)_2(aq) -----------> CaCl_2(aq) + 2HNO_3(aq)

2 H⁺_(aq) + 2 Cl^-_(aq) + Ca²⁺_(aq) + 2NO^3-_(aq) -------> Ca²⁺_(aq) + 2Cl^-_(aq) + 2H⁺_(aq) + 2NO₃- _(aq)

2. Using the net ionic equations, compare the products formed with the observations made and identify each reagant bottle

1. A = HCl

2. B = K2CO3

3. C = Ca(NO3)2

According to the observations:

A + B

HCl + K₂CO₃ -------> KCl + CO₂ + H₂O

When these solutions are mixed there will be evolution of carbon di oxide gas.

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A + C

HCl + Ca(NO₃)₂ ---------> CaCl₂ + HNO₃

When these solutions are reacted No Visible Changes are observed

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B + C

K₂(CO₃)₂ + Ca(NO₃)₂ -----------> ₂KNO₃ + CaCO₃

When these solutions are mixed A White Precipitaion is formed