In dry cell, what acts as a negative electrode?
Zinc
Graphite
Ammonium chloride
Manganese dioxide
A.
Zinc
In a dry cell, zinc acts as a negative electrode. In this cell, the outer zinc container is the negatively charged terminal.
At anode (negative terminal)
Zn(s) → Zn2+(aq) + 2e-
At cathode (positive terminal)
2MnO2(s) + 2e- + 2NH4Cl(aq) → Mn2O3(s) + 2NH3(aq) + H2O (l)+ 2Cl-
The reaction takes place in two steps as
Identify the reaction intermediate.
NO2Cl (g)
NO2(g)
Cl2(g)
Cl(g)
The relation between solubility of a gas in liquid at constant temperature and external pressure is stated by which law?
Raoult's law
van't Hoff- Boyle's law
van't Hoff- Charles' law
Henry's law
Identify the metal that forms colourless compounds.
Iron (Z = 26)
Chromium (Z = 24)
Vanadium (Z=23)
Scandium (Z =21)
The rate constant and half-life of a first order reaction are related to each other as
t1/2 = 0.693 k
k = 0.693 t1/2
Which of the following is a neutral complex?
[Pt(NH3)2Cl2]
[Co(NH3)6]Cl3
[Ni(NH3)6]Cl2
K4[Fe(CN)6]
Identify the compound amongst the following of which 0.1 M aqueous solution has highest boiling point.
Glucose
Sodium chloride
Calcium chloride
Ferric chloride