using Zinc powder instead of Zinc granules
using dilute instead of concentrated hydrochloric acid
cooling the container in which the mixture is placed
using an alloy of zinc instead of pure zinc
using hydrogen chloride gas instead of hydrochloric acid solution
Correct answer is A
No explanation has been provided for this answer.
Pure sodium chloride does not conduct electricity
Potassium fluoride prevents the sodium produced from attacking the electrodes
Potassium fluride increases conductivity
Potassium fluride reduces the temperature at which sodium chloride fuses
the potassium fluride acts as a catalyst
Correct answer is D
No explanation has been provided for this answer.
sodium ions
potassium ions
lithium ions
calcium ions
magnesium ions
Correct answer is B
No explanation has been provided for this answer.
Copper can best be purified by
roasting the impure copper in a blast furnace
heating the oxide with coke
electrolyzing a copper (ll) salt solution using the impure copper as the anode
converting the impure copper to a trioxonitrate (V)
washing the impure copper with sodium hydroxide solution
Correct answer is C
No explanation has been provided for this answer.
Which of the following carbohydrates does NOT usually occur in the crystalline form?
Fructose
Glucose
Sucrose
Maltose
Cellulose
Correct answer is E
No explanation has been provided for this answer.