The scale formation in a kinetic used for boiling water is caused by the presence in water of?
calcium sulphate
calcium carbonate
calcium hydrogen carbonate
calcium hydroxide
magnesium sulphate
Correct answer is C
The scale is produced when soluble Ca(HCO3)2 breaks down on heating to form insoluble CaCO3
eqn Ca (HCO3)2(aq) -----> CaCO3 (s) + CO2 (g) + H2O (l)
What happens when the nitrates of potassium, calcium, zinc and copper are separately heated?
All the nitrate will decompose to their respective metals
The nitrates of calcium and potassium will decomposes to their nitrites
Only copper nitrate decomposes to the metal
Only the nitrates of zinc and copper will decompose to their oxides
The nitrates of calcium, zinc and copper decompose to their oxides
Correct answer is E
The nitrates of calcium, zinc and copper decompose to their metal oxides
There were more aluminium atoms in Q than P
The heat given off in retarded the reaction
Q generated more pressure than P during the reaction
P generated more pressure than Q
Q has a greater surface area for the reaction than P
Correct answer is E
No explanation has been provided for this answer.
1.0 x 1021
6.6 x 1021
2.0 x 1022
1.0 x 1022
5.4 x 1023
Correct answer is C
1 Mole or 27 gms of Al contains 6 x 1021 atoms
0.9 gms of Al will contain (6 x 1023 x 0 g)/(27 1) = 0.2 x 1023 or 1022
Copper
Iron
Lead
Potassium
Zinc
Correct answer is D
No explanation has been provided for this answer.