Question

a particle diagram for a chemical reaction is shown.
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which of the following chemical changes is best represented by the particle diagram shown?
(water molecules are omitted for clarity)
3agno3(aq)+mgi2(aq)→2agi(s)+mg(no3)2(aq)
agno3(aq)+kcl(aq)→agcl(s)+kno3(aq)
2hcl(aq)+ba(oh)2(aq)→bacl2(s)+2h2o(l)
mnso4(aq)+k2s(aq)→mns(aq)+k2so4(aq)

Explanation:

Step1: Analyze the reactants and products in the particle diagram

The particle diagram shows a precipitation reaction. In a precipitation reaction, two aqueous solutions react to form an insoluble solid (precipitate).

Step2: Analyze each option

• Option A:

$$3AgNO_{3}(aq)+MgI_{2}(aq)\to 2AgI(s)+Mg(NO_{3})_{2}(aq)$$
This is a precipitation reaction as \(AgI\) is insoluble. But the stoichiometry in terms of the number of ions in the particle diagram (if we consider the ratio of cations and anions) may not match.

• Option B:

$$AgNO_{3}(aq)+KCl(aq)\to AgCl(s)+KNO_{3}(aq)$$
This is a precipitation reaction (\(AgCl\) is insoluble). If we assume the black circles as \(Ag^{+}\) and white circles as \(Cl^{-}\) (or vice - versa), the ratio of reactant ions (1:1) and the formation of a 1:1 precipitate (\(AgCl\)) can be represented in a simple particle diagram.

• Option C:

$$2HCl(aq)+Ba(OH)_{2}(aq)\to BaCl_{2}(aq)+2H_{2}O(l)$$
This is an acid - base neutralization reaction (not a precipitation reaction as \(BaCl_{2}\) is soluble in water).

• Option D:

$$MnSO_{4}(aq)+K_{2}S(aq)\to MnS(aq)+K_{2}SO_{4}(aq)$$
Since \(MnS\) is soluble in water (assuming no special conditions like very low solubility not indicated), this is not a precipitation reaction.

Answer:

B. \(AgNO_{3}(aq)+KCl(aq)\to AgCl(s)+KNO_{3}(aq)\)