For the answer to the question above, <span>The formula for freezing point depression is </span>
<span>ΔTf = mkfi </span>
<span>kf is the freezing point constant </span>
<span>i is the Van't Hoff factor which in this case is 1 </span>
<span>m is molality (moles of solute/kg of solvent) </span>
<span>ΔTf is temperature change </span>
<span>ΔTf is 2.17 °C, the molality is the amount of solute Quinine </span>
<span>in the solvent cyclohexane. We cannot calculate moles therefore we need to substitute moles with g/mm. </span>
<span>moles = g/mm so molality=(g/mm)/kg </span>
<span>molality = (0.845/mm)/0.025 = 33.8/mm </span>
<span>2.17 = 33.8/mm(20.8) rearrange </span>
<span>mm = (33.8/2.17)(20.8) = 324g/mol</span>
Answer:
<h2>4 moles</h2>
Explanation:
To find the number of moles in a substance given it's number of entities we use the formula
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
We have the final answer as
<h3>4 moles</h3>
Hope this helps you
To solve this question, think about which one of these options is a DIRECT effect of sea levels rising.
Choice A: If sea levels rise, they would start to cover up land that's at sea level, areas like beaches or coastal cities for example.
Choice B: Fossil fuels cause global warming. This is about the effects of global warming, not the causes.
Choice C: Not relevant. It doesn't mention alternative energy at all in this.
Choice D: Again, effects, not causes (see Choice B explanation).
The correct answer is... CHOICE A
Answer:
The answer is Bob
Explanation:
The science exist to kinds of measurements base units and derive units of measurement.
Base units are the ones that measure: length, mass, time, electric current, temperature, luminous intensity and amount of substance.
Derivative units of measurement are obtain when we combine the base units.
Know from your question
Bob measures length is a base unit
Jill measures density is a derivative unit, is the combination of mass and volumen
Kim measures mass is a base unit
Steve measures brightness is a base unit.
mr oxygen= 16. 16 x 3= 48
mr Al2O3= 27 + 27 + 48= 102
(48/102) X 100%= 47.05% oxygen
