In order to find the number of moles with a given mass of Helium, we need to use its molar mass, which is 4.0026g/mol, therefore we will have:
4.0026g = 1 mol of Helium
91.5g = x moles of Helium
x = 22.86 moles of Helium in 91.5 grams
HEY DEAR..
The particles of light known as photon.
HOPE ITS HELPFULL
Answer:- 2.92 kJ of heat is released.
Solution:- We have water at 100 degree C and it's going to be cool to 15 degree C.
So, change in temperature,
= 15 - 100 = -85 degree C
mass of water, m = 8.2 g
specific heat of water, c = 
The equation used for solving this type of problems is:

Let's plug in the values in the equation and solve it for q which is the heat energy:
q = (8.2)(4.184)(-85)
q = -2916.248 J
They want answer in kJ. So, let's convert J to kJ and for this we divide by 1000.

q = -2.92 kJ
Negative sign indicates the heat is released. So, in the above process of coiling of water, 2.92 kJ of heat is released.
Answer:
58.443 g/mol
Explanation:
The molar mass of NaCl is the sum of the molar masses of the individual atoms:
Na: 22.989770 g/mol
Cl: 35.453 g/mol
The total molar mass is ...
NaCl: 58.443 g/mol
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The molar mass does not depend on whether the material is in solution or in any other form.