Answer:
I cannot give you all the answer but I can help you to solve those.
Explanation:
The first question:
How many grams are there in 7.5×
molecules of 
?
So we need to find the molecular mass first, use your periodic table,
And then we can find out 2+32+16×4=98 g/mol
Then, we need to find how many moles, by using Avogadro's constant:
Avogadro's constant: 1 mole = 6.02×
∴
=1.25 mol(2d.p.)
Lastly, find the grams using the formula 
m=Mn
m=1.25*98
m=122.5g
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In conclusion, use those formula to help you:
(which M = molecular mass(atomic mass) m=mass of the substance and n = moles)
Avogadro's constant: 
Answer:
235 miles equals 5,280 feet
Explanation:
Answer:
Follows are the solution:
Explanation:
A + B = C
Its response decreases over time as well as consumption of a reactants.
r = -kAB
during response A convert into 2x while B convert into x to form 3x of C
let's y = C
y = 3x
Still not converted sum of reaction
for A: 100 - 2x
for B: 50 - x
Shift of x over time
Integration of x as regards t
![\frac{1}{[(100 - 2x)(50 - x)]} dx = -k dt\\\\\frac{1}{2[(50 - x)(50 - x)]} dx = -k dt\\\\\ integral\ \frac{1}{2[(50 - x)^2]} dx =\ integral [-k ] \ dt\\\\\frac{-1}{[100-2x]} = -kt + D \\\\](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B%5B%28100%20-%202x%29%2850%20-%20x%29%5D%7D%20dx%20%3D%20-k%20dt%5C%5C%5C%5C%5Cfrac%7B1%7D%7B2%5B%2850%20-%20x%29%2850%20-%20x%29%5D%7D%20dx%20%3D%20-k%20dt%5C%5C%5C%5C%5C%20integral%5C%20%20%5Cfrac%7B1%7D%7B2%5B%2850%20-%20x%29%5E2%5D%7D%20dx%20%3D%5C%20integral%20%5B-k%20%5D%20%5C%20dt%5C%5C%5C%5C%5Cfrac%7B-1%7D%7B%5B100-2x%5D%7D%20%3D%20-kt%20%2B%20D%20%5C%5C%5C%5C)
D is the constant of integration
initial conditions: t = 0, x = 0
![\frac{-1}{[100-2x]} = -kt + D \\\\\frac{ -1}{[100]} = 0 + D\\\\D= \frac{-1}{100}\\\\](https://tex.z-dn.net/?f=%5Cfrac%7B-1%7D%7B%5B100-2x%5D%7D%20%3D%20-kt%20%2B%20D%20%20%20%5C%5C%5C%5C%5Cfrac%7B%20-1%7D%7B%5B100%5D%7D%20%3D%200%20%2B%20D%5C%5C%5C%5CD%3D%20%5Cfrac%7B-1%7D%7B100%7D%5C%5C%5C%5C)
hence we get:
![\frac{-1}{[100-2x]}= -kt -\frac{1}{100}\\\\or \\\\ \frac{1}{(100-2x)} = kt + \frac{1}{100}](https://tex.z-dn.net/?f=%5Cfrac%7B-1%7D%7B%5B100-2x%5D%7D%3D%20-kt%20-%5Cfrac%7B1%7D%7B100%7D%5C%5C%5C%5Cor%20%5C%5C%5C%5C%20%5Cfrac%7B1%7D%7B%28100-2x%29%7D%20%3D%20kt%20%2B%20%5Cfrac%7B1%7D%7B100%7D)
after t = 7 minutes , 
Insert the above value x into 
equation 
to get k.
therefore plugging in the equation the above value of k
Let y = C
, calculate C:
y = 3x
amount of C formed in 28 mins
plug t = 28
therefore amount of C formed in 28 minutes is = 3x = 144.78 grams
C:
y= 136.5 =137
Answer:
Not doubled
Explanation:
The equation below represent the ideal gases relationship
PV ÷ T = constant
Here
P denotes pressure,
V denotes volume,
T denotes temperature in degrees Kelvin
Now
20 ° c = 273 + 20
= 293 K
And,
40 ° c = 313 K
So,
V = Vo. 313 K ÷ 293 K = 1.07 Vo
So, the volume is NOT doubled.
In the case when the temperature would be determined in degrees celsius at 0 degrees so the volume would be zero
I think the correct answer from the choices listed above is option C. Lotions applied during winter season moisturize the skin very quickly. This is because the oils in the lotion enter the skin cells by means of facilitated diffusion. Hope this answers the question.
