Which of the following samples will react fastest with dilute trioxonitrate (V) acid?
5 g of lumps of CacO3 at 25°C
5 g of powered CacO3 at 25°
5 g of lumps of CaCO3 at 50°C
5 g of powered CaCO3 AT 50°C
Correct answer is D
No explanation has been provided for this answer.
Iron galvanized with zinc is cathodically protected from corrosion. This is because?
zinc has a more positive oxidation potential than iron
zinc has less positive oxidation potential than iron
bith have the same oxidation potential
zinc is harder than iron
Correct answer is A
Iron galvanized with zinc is cathodically protected from corrosion because Zinc has a more positive oxidation potential than iron. This means that Zinc will preferentially corrode, acting as a sacrificial anode.
+2492
+848
-848
-2492
Correct answer is C
Heat of formation = Heat of products - Heat of reactants
= - 1670 - (- 822)
= - 1670 + 822
= - 848 kJ
In the reaction 1O-3 + 5l- + 6H+ → 312 + 3H2O, the oxidizing agent is?
H+
l-
1O-
l2
Correct answer is C
No explanation has been provided for this answer.
+7 to +3
+6 to +3
+5 to +3
-2 to +3
Correct answer is A
No explanation has been provided for this answer.