48,000
96,000
192,000
384,000
576,000
Correct answer is D
48,000 coulombs are required to discharge 0.5 mole of Na
∴ 1 m will be discharged by 2 x 48,000 = 96,000 coulombs
2 moles of Na will be discharged by 2 x 96,000
= 192,000
For lead (Pb) two electrons are involved.
∴ Number or coulombs required to discharged 2 moles of Pb = 2 x 192,000 = 384,000 coulombs
28.8 cm3 of nitrogen at 15°C is cooled to O°C at constant pressure, the new volume of nitrogen is?
17.4 cm3
14.7 cm3
27.3 cm3
31.7 cm3
Correct answer is C
(V1)/(T1) = (V2)/(T2) (288 cm3)/(288) = (V2)/(273)
V2 = (288 x 273)/(288) = 273 cm3
Which of the following statements about phosphorus is NOT correct?
Phosphorus is a solid mineral
Phosphorus is obtained by oxidation reaction of phosphate
Phosphorus exists in two allotropic forms
Both forms of phosphorus are interconvertible
Yellow phosporus ignites when rubbed on a rough surface
Correct answer is C
The main allotropes of phosphorus include the white phosphorus, red phosphorus and black phosphorus.
addition products of long chain fatty acids and alkali
addition products of long-chain fattyy acids and glycerol
condensation products of long-chain fatty acids and glycerol
condensation products of formaldehyde and glycerol
liquids at 20°C
Correct answer is C
No explanation has been provided for this answer.
its density decreases
it solidifies
its temperature decreases
its temperature increases
its temperature remains unchanged
Correct answer is D
Compressed air is a gas, or a combination of gases, that has been put under greater pressure than the air in the general environment.
When you pressurize a gas by compressing it into a container, you're putting all those molecules into a smaller volume of space and you're adding potential energy by the compression.
Gay Lussac's Law - states that the pressure of a given amount of gas held at constant volume is directly proportional to the Kelvin temperature.