Classify these salts as either soluble or insoluble: $NH_4CI, PbCl_2, BaSO_4, K_2SO_4, Na_2CO_3, NaNO_3, (NH_4)_2CO_3, MgCO_3, AgNO_3, AgCl$.
Answer (1)
N H 4 Cl : Soluble, P b C l 2 : Insoluble, B a S O 4 : Insoluble, K 2 S O 4 : Soluble, N a 2 C O 3 : Soluble, N a N O 3 : Soluble, ( N H 4 ) 2 C O 3 : Soluble, M g C O 3 : Insoluble, A g N O 3 : Soluble, A g Cl : Insoluble. N H 4 Cl : S o l u b l e , P b C l 2 : I n so l u b l e , B a S O 4 : I n so l u b l e , K 2 S O 4 : S o l u b l e , N a 2 C O 3 : S o l u b l e , N a N O 3 : S o l u b l e , ( N H 4 ) 2 C O 3 : S o l u b l e , M g C O 3 : I n so l u b l e , A g N O 3 : S o l u b l e , A g Cl : I n so l u b l e
Explanation
Problem Analysis We are given a list of chemical compounds and asked to classify each as either soluble or insoluble in water. To do this, we will apply the general solubility rules.
Solubility Rules Here are the general solubility rules:
Salts of alkali metals (Group 1A) and ammonium ( N H 4 + ) are soluble.
Nitrates ( N O 3 − ), acetates ( C 2 H 3 O 2 − ), and perchlorates ( Cl O 4 − ) are soluble.
Halides (Cl − , Br − , I − ) are soluble, except those of silver ( A g + ), lead ( P b 2 + ), and mercury ( H g 2 2 + ).
Sulfates ( S O 4 2 − ) are soluble, except those of strontium ( S r 2 + ), barium ( B a 2 + ), lead ( P b 2 + ), and calcium ( C a 2 + ).
Carbonates ( C O 3 2 − ), phosphates ( P O 4 3 − ), chromates ( C r O 4 2 − ), and sulfides ( S 2 − ) are generally insoluble, except those of alkali metals and ammonium.
Applying Solubility Rules
N H 4 Cl : Contains ammonium ( N H 4 + ), so it is soluble .
P b C l 2 : Contains chloride ( C l − ) and lead ( P b 2 + ), so it is an exception and is insoluble .
B a S O 4 : Contains sulfate ( S O 4 2 − ) and barium ( B a 2 + ), so it is an exception and is insoluble .
K 2 S O 4 : Contains potassium ( K + ), an alkali metal, so it is soluble .
N a 2 C O 3 : Contains sodium ( N a + ), an alkali metal, so it is soluble .
N a N O 3 : Contains sodium ( N a + ), an alkali metal, and nitrate ( N O 3 − ), so it is soluble .
( N H 4 ) 2 C O 3 : Contains ammonium ( N H 4 + ), so it is soluble .
M g C O 3 : Contains carbonate ( C O 3 2 − ), so it is generally insoluble. Magnesium ( M g 2 + ) is not an exception, so it is insoluble .
A g N O 3 : Contains nitrate ( N O 3 − ), so it is soluble .
A g Cl : Contains chloride ( C l − ) and silver ( A g + ), so it is an exception and is insoluble .
Final Classifications Therefore, the classifications are:
N H 4 Cl : Soluble
P b C l 2 : Insoluble
B a S O 4 : Insoluble
K 2 S O 4 : Soluble
N a 2 C O 3 : Soluble
N a N O 3 : Soluble
( N H 4 ) 2 C O 3 : Soluble
M g C O 3 : Insoluble
A g N O 3 : Soluble
A g Cl : Insoluble
Examples
Understanding solubility is crucial in many real-world applications. For instance, in water treatment, knowing whether a compound is soluble helps in designing effective filtration and purification processes. In environmental science, it's important for predicting the transport and fate of pollutants in aquatic systems. In medicine, the solubility of drugs affects their absorption and distribution in the body, influencing their effectiveness. Even in cooking, the solubility of ingredients like salt and sugar determines how well they dissolve and blend into recipes.
