Shazia adds a small amount of ammonium chloride salt to a beaker of water. The
temperature of the water decreases from 21 °C to 17 °C. Which type of reaction has
occurred and why?
Answers
Answer:
When dilute HCl is added to a salt Q, a brisk effervescence is produced and the gas turns lime water milky.
This indicates presence of carbonate ion.
CO
3
2+
+2HCl→H
2
O+CO
2
↑+2Cl
−
Ca(OH)
2
+CO
2
→CaCO
3
↓+H
2
O
When NH
4
OH solution is added to the above mixture (after adding dilute HCl), it produces a white precipitate which is soluble in excess NH
4
OH solution.
This indicates presence of Zn(II) ions.
Zn
2+
+2NH
4
OH→Zn(OH)
2
↓+2NH
4
+
Zn(OH)
2
+4NH
4
OH(excess)→
(water soluble)
[Zn(NH
3
)
4
](OH)
2
+4H
2
O
Hence, the salt Q is zinc carbonate ZnCO
3
please mark me brain list I need only one more brain list please dear
Answer:
When dilute HCl is added to a salt Q, a brisk effervescence is produced and the gas turns lime water milky.
This indicates presence of carbonate ion.
CO
3
2+
+2HCl→H
2
O+CO
2
↑+2Cl
−
Ca(OH)
2
+CO
2
→CaCO
3
↓+H
2
O
When NH
4
OH solution is added to the above mixture (after adding dilute HCl), it produces a white precipitate which is soluble in excess NH
4
OH solution.
This indicates presence of Zn(II) ions.
Zn
2+
+2NH
4
OH→Zn(OH)
2
↓+2NH
4
+
Zn(OH)
2
+4NH
4
OH(excess)→
(water soluble)
[Zn(NH
3
)
4
](OH)
2
+4H
2
O
Hence, the salt Q is zinc carbonate ZnCO
3
Explanation: