The simplified model of the hall effect proved that the current (electric) in metals are carried by electrons and not protons. The hall effect introduced the hall coefficient which is the ratio of the induced electric field to the current density x applied magnetic field. This coefficient is unique for each type of metal.
Answer:
NaI > Na2SO4 > Co Br3
meaning that NaI has the highest freezing point, and Co Br3 has the lowest freezing point.
Explanation:
The freezing point depression is a colligative property.
That means that it depends on the number of solute particles dissolved.
The formula to calculate the freezing point depression of a solution of a non volatile solute is:
ΔTf = i * Kf * m
Where kf is a constant, m is the molality and i is the van't Hoff factor.
Molality, which is number of moles per kg of solvent, counts for the number of moles dissolved and the van't Hoff factor multipllies according for molecules that dissociate.
The higher the number of molecules that dissociate, the higher the van't Hoff, the greater the freezing point depression and the lower the freezing point.
As the question states that you assume equal concentrations (molality) and complete dissociation you just must find the number of ions generated by each solute, in this way:
NH4 I → NH4(+) + I(-) => 2 ions
Co Br3 → Co(+) + 3 Br(-) => 4 ions
Na2SO4 → 2Na(+) + SO4(2-) => 3 ions.
So, Co Br3 is the solute that generate more particles and that solution will exhibit the lowest freezing point among the options given, Na2SO4 is next and the NaI is the third. Ordering the freezing point from higher to lower the rank is NaI > Na2SO4 > CoBr3, which is the answer given.
Answer: (3) 15
Explanation: We criss-cross down the oxidation numbers to get the subscripts for the correct formulas. That means the X has an oxidation number of 5. The element with the + oxidation number is always written first so it is +5. Of the groups names, only group 15 has +5 as an oxidation number.
Answer:
No, the puddle was formed because of the sun, because if there was snow and it rained then it would have turned slippery or icy
Answer:C.He should locate the chloroform stored in a dark container in chemical storage and should take it to the fume hood to pour.
Explanation:
The statement of the question clearly states that chloroform is sensitive to light and it's vapour is toxic.
If a substance is sensitive to light, then it must be stored in a dark bottle. This is because. If a substance that is sensitive to light is stored in a transparent container, it may be decomposed by light.
Being a substance whose fumes are toxic, Malik should pour the liquid in a fumes hood so that he does not inhale the fumes.
