Answer:
neck
Explanation:
through the neck and opening of the thermos, where there is no vacuum.. hence heat is easily transmitted resulting into heat loss
Answer:
72.4%
Explanation:
Step 1: Write the balanced equation
2 Cu + S ⇒ Cu₂S
Step 2: Calculate the theoretical yield, in moles, from 0.0970 moles of Cu
The molar ratio of Cu to Cu₂S is 2:1.
0.0970 mol Cu × 1 mol Cu₂S/2 mol Cu = 0.0485 mol Cu₂S
Step 3, Convert the theoretical yield to mass
The molar mass of Cu₂S is 159.16 g/mol.
0.0485 mol × 159.16 g/mol = 7.72 g
Step 4: Calculate the percent yield
We will use the following expression.
%yield = experimental yield/theoretical yield × 100%
%yield = 5.59 g/7.72 g × 100% = 72.4%
Answer:
For the control experiment: of aqueous solution of erioglaucine has absorbance of
From Lambert-Beer's law we know:
Here; e is the molar absorptivity coefficient of erioglaucine
l = length of cuvette in which the solution is taken =
A sorbance by the erioglaucine = total absorbance - absorbance by distilled
So; by putting the values in the above equation; we get:
So;
The molar absorptivity coefficient of erioglaucine is
The absorbance of erioglaucine in distilled water (contaminated with metal ions) is:
The absorbance of distilled water is
So; absorbance of erioglaucine itself is :
Again using Lambert Beer law; we get:
c = 0.198/5.65 M = 0.035 M
The concentration of the erioglaucine is
Explanation:
The answer is not D, because water creates turgidity.
The answer is not C, because water is important in many biological reactions.
The answer is either A, or B. Knowing that water composes almost 75% of the body, you can assume that It is a common substance, for A, or you could know that is allows reactions to occur more easily, acting as a sort of catalyst, for answer B.
A or B. Your call for the final answer.