"High temperatures make the gas molecules move more quickly" is the one sentence among all the choices given in the question that most likely explains why this reaction is carried out at high temperature. The correct option among all the options that are given in the question is the third option or option "C".
This question seems to be an essay question from experiment. Different solution of oxidizing agent will have different strength. Sulfuric acid or H2SO4 is weaker oxidizing agent when compared to nitric acid (HNO3). In this case, if you subtitute the H2SO4 you wouldn't be able to get the same result for the experiment.
Answer:
Sample A is a mixture
Sample B is a mixture
Explanation:
For sample A, we are told that the originally yellow solid was dissolved and we obtained an orange powder at the bottom of the beaker. Subsequently, only about 30.0 g of solid was recovered out of the 50.0g of solid dissolved. This implies that the solid is not pure and must be a mixture. The other components of the mixture must have remained in solution accounting for the loss in mass of solid obtained.
For sample B, we are told that boiling started at 66.2°C and continued until 76.0°C. The implication of this is that B must be a mixture since it boils over a range of temperatures. Pure substances have a sharp boiling point.
<u>Answer</u>:-
Name of element = Lead
Symbol ♾ of Lead = Pb
Atomic no. = 82
Atomic mass = 207.2 amu
No. of protons = 82
No. of electrons = 82
Yes, lead(Pb) is a metallic element and certainly it has 6 electron shells which means 6 energy level.
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