A metal M displaces zinc from ZnCl solution
This shows that
electrons flow from zinc to M
M is more electropositive than zinc
M is more electonegative than zinc
zinc is more electropositive than M
Correct answer is B
No explanation has been provided for this answer.
What number of moles of Cu 2+ will be deposited by 360 coulombs of electricity?
[f = 96500 C mol -1]
5.36 x 10 -4 mole
1. 87 x 10 10 -3 mole
9. 35 x 10 -4 mole
3. 73 x 10 -3
Correct answer is B
Cu\(^{2+}\) + 2e\(^{-}\)\(_{(aq)}\) \(\rightarrow\) Cu\(_{(s)}\)
Liberating 1 mole of Cu
2 x 1F = 2 x 96,500C = 193,000C of electricity is needed
Hence, 193,000C = 1 mole
360C of electricity = \(\frac{360C \times 1 mol}{193,000C}\)
= 0.001865 mol
= 1.87 x 10\(^{-3}\) moles
Na2O2(s) + H2O(1) → NaOH(s) +O2(g)
The substance that is oxidized in the reaction above is
2NaO2(s)
NaOH(aq)
H2O(1)
O2(g)
Correct answer is C
No explanation has been provided for this answer.
The oxidation number of boron in NaBH 4 is
-3
-1
+1
+3
Correct answer is D
No explanation has been provided for this answer.
A major factor considered in selecting a suitable method for preparing a simple salt is its
Crystalline from
melting point
reactivity with dilute acids
solubility in water
Correct answer is D
No explanation has been provided for this answer.