The answer is D, alters the test variable, and observes the effects on other outcome variables.
Answer:
8.55x10^22 molecules
Explanation:
From the question given, the following data were obtained:
Density = 1g/mL
Volume = 2.56mL
Mass =?
Density = Mass /volume
Mass = Density x volume
Mass = 1 x 2.56
Mass = 2.56g
Now let us convert this mass (i.e 2.56g) of water to mole
Molar Mass of H2O = (2x1) + 16 = 2 + 16 = 18g/mol
Mass of H2O = 2.56g
Number of mole of H2O=? Number of mole = Mass /Molar Mass
Number of mole of H2O = 2.56/18
Number of mole of H2O = 0.142mol
From Avogadro's hypothesis, 1mole of any substance contains 6.02x10^23 molecules. This means that 1mole of H2O contains 6.02x10^23 molecules.
Now if 1mole of H2O contains 6.02x10^23 molecules, then 0.142mol of H2O will contain = 0.142 x 6.02x10^23 = 8.55x10^22 molecules
I haven’t yet, still working on it though
Answer:
B
Explanation:
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Answer:
![[A]_0=0.400M](https://tex.z-dn.net/?f=%5BA%5D_0%3D0.400M)
Explanation:
Hello.
In this case, since the first-order reaction is said to be linearly related to the rate of reaction:
![r=-k[A]](https://tex.z-dn.net/?f=r%3D-k%5BA%5D)
Whereas [A] is the concentration of hydrogen peroxide, when writing it as a differential equation we have:
![\frac{d[A]}{dt} =-k[A]](https://tex.z-dn.net/?f=%5Cfrac%7Bd%5BA%5D%7D%7Bdt%7D%20%3D-k%5BA%5D)
Which integrated is:
![ln(\frac{[A]}{[A]_0} )=-kt](https://tex.z-dn.net/?f=ln%28%5Cfrac%7B%5BA%5D%7D%7B%5BA%5D_0%7D%20%29%3D-kt)
And we can calculate the initial concentration of the hydrogen peroxide as follows:
![[A]_0=\frac{[A]}{exp(-kt)}](https://tex.z-dn.net/?f=%5BA%5D_0%3D%5Cfrac%7B%5BA%5D%7D%7Bexp%28-kt%29%7D)
Thus, for the given data, we obtain:
![[A]_0=\frac{0.321M}{exp(-2.54x10^{-4}s^{-1}*855s)}](https://tex.z-dn.net/?f=%5BA%5D_0%3D%5Cfrac%7B0.321M%7D%7Bexp%28-2.54x10%5E%7B-4%7Ds%5E%7B-1%7D%2A855s%29%7D)
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