Energetics
What is entropy?
Measure of disorder of a system
What is the colour of the sodium flame?
Yellow
What is the oxidation number of nitrogen in nitrogen dioxide?
+4
What is the shape of a BF3 molecule?
trigonal planar
Who is the head of state of New Zealand?
King Charles
What is the equation for calculating Gibbs free energy?
delta G= delta H - T x delta S
What is the electron configuration of Fe2+?
1s2, 2s2, 2p6, 3s2, 3p6, 3d6
What is the definition of an oxidation reaction?
Loss of electrons
What is Faraday's constant?
965000C/mol
What is the Samoan word for chicken which is also a name of an extinct bird in NZ?
Moa
Calcium carbonate is decomposed with heat. Describe and explain the change in entropy of the system.
entropy of the system increases as gas is formed
What are the bond angles found in PCl5?
90 and 120 degrees
What are 3 conditions needed for standard electrode potential?
1mol dm-3
298K
1atm gas
Explain why HI have higher boiling point than HCl.
Bigger molecules with more electrons, stronger van der waals forces.
What is a famous exclamation attributed to Archimedes after he found out how to measure density of an irregular object?
Eureka
A reaction is exothermic and entropy of the system decreases. What can you say about the spontaneity of the reaction?
Reaction is spontaneous at lower temperature.
What mechanism of reaction is used when CH3Cl reacts to form methanol?
Sn2
What are the observations when NaBr(aq) is electrolysed?
Cathode: Colourless bubbles
Anode: red solutions
What is the observation when PCl5 dissolve in water?
What is the Maaori name for Mt Cook in South Island/ Te Waipounamu?
Aoraki
Explain why solubility of group 2 sulfate decreases down the group. (3 points)
2. As group 2 ion becomes bigger both hydration enthalpy and lattice enthalpy becomes less exothermic.
3. hydration enthalpy changes at greater extent than lattice enthalpy.
What is the observation when propanone is mixed with sodium hydroxide and Iodine?
Yellow precipiatete
Using the data booklet,
What will be the observation when following substances are mixed together?
Cu2+, I2, Zn2+ and Fe2+
No observation
What are the changes in oxidation number of Cl when chlorine gas is reacted with sodium hydroxide in hot temperature?
-1 and +5
How many points did Mr Kim score in the 2024 Leavers vs Staff Basketball game?