Which of the species
KClO2, NH4Br, HNO2, PbS
is/are insoluble in water?
1. NH4Br and NH3
2. KClO3
3. PbS
4. HNO2
5. All of these
3. PbS
PbS
To determine which species are insoluble in water, we need to look at the solubility rules for common compounds. Solubility rules provide guidelines on which compounds are soluble or insoluble in water.
1. NH4Br: To determine the solubility of NH4Br, we refer to the solubility rules. Rule 1 states that all compounds containing ammonium (NH4+) are soluble in water. Therefore, NH4Br is soluble in water.
2. KClO3: Rule 1 also applies to potassium compounds (K+), making KClO3 soluble in water.
3. PbS: Rule 4 states that sulfides (S2-) are generally insoluble in water, except those of alkali metals and ammonium. Since PbS contains a sulfide ion and lead (Pb) is not an alkali metal or ammonium, PbS is insoluble in water.
4. HNO2: Nitrate compounds (NO3-) are generally soluble, according to Rule 1. Therefore, HNO2 is soluble in water.
Based on the above analysis, the answer is 3. PbS is the only species that is insoluble in water out of the given options.