Question

In double replacement reactions, the two cations switch places.

AB+ CD →→ AD + CB
Switch the positive ions, criss-cross charges on the new products if needed, and decide if products are
aqueous (soluble) or solid (insoluble). Provide the formula for the precipitate, if there is one. DO NOT
BALANCE.
14. Li₂S (aq) + AgNO3(aq)
15. BaCl2 (aq) +
Na₂CO3(aq)
16. Al₂(SO4)3 (aq) + Na3PO4 (aq)
17. BaCl₂ (aq) +
NaCl +
H₂PO4 (aq) → HCI +
+ LINO,
+ AIPO4
ppt
ppt
ppt
ppt

Answer 1

Double replacement reactions involve two compounds in aqueous solution exchanging anions or cations. Products can include a precipitate if one of the new compounds is insoluble in water, based on solubility rules. Examples include the formation of Ag₂S, BaCO₃, and AlPO₄ as precipitates in different reactions.

Step-by-step explanation:

Understanding Double Replacement Reactions

In double replacement reactions, two compounds exchange their cations or anions to form two new compounds. This type of reaction can result in the formation of a precipitate, a substance that is insoluble in water and falls out of the solution. The solubility of the products is key for predicting whether a precipitate will form and is determined using solubility rules.

For the given reactions:

• Al₂(SO₄)₃ (aq) + Na₃PO₄ (aq) will produce AlPO₄(s) and Na₂SO₄(aq). Aluminum phosphate (AlPO₄) is the precipitate because it is insoluble in water.
• BaCl₂ (aq) + H₂PO₄ (aq) does not yield a precipitate since none of the products formed, HCl and LINO, are insoluble in this context.

It's important to remember not to balance the equations or to dissociate the solid precipitates into ions in the net ionic equations.