So its temperature will not rise, since kinetic energy of molecules remains the same. The quantity of heat absorbed or released when a substance changes its physical phase at constant temperature (e g. From solid to liquid at melting point or from liquid to gas at boiling point) is termed as its latent heat.
Mass:20g
Mole=20/[2(23)+16]
=0.32 mil
Using dimensional analysis, we can find the moles of strontium by comparing the mass of strontium to it's atomic mass.
You can find the atomic mass of Sr on the periodic table:
Atomic Mass Sr = 87.62g/mol
In case you are not familiar, dimensional analysis works like this:
(what we know) x (conversion factor) = what we are looking for
The conversion factor compares the units of what we know to the units of what we are looking for. In this case, the conversion factor is:
1 mol/87.62g
The important thing to note about the conversion factor is that you want to be able to cancel out the units of your given measurement (in this case, it is the mass)
So, our full solution will be:
moles Sr = (175.24 g)x(1 mol/87.62 g)
(cancel out the mass units)
moles Sr = 175.24 x 1 mol/87.62
= 2.00 mol Sr
Hope this helped you!
Answer:
Molar mass = 1.111 × 10⁻⁵ g/mol
Explanation:
Given data:
Mass of polyethylene = 1.36 g
Volume = 100 mL (0.1 L )
Pressure = 1.86 torr (1.86/760 = 0.003 atm)
Temperature = 25 °C = 25 °C + 273.15 = 298.15 K
Molar mass of polyethylene = ?
Solution :
PV =nRT
n = PV/RT
n = 0.003 atm × 0.1 L / 0.0821 atm. L . mol⁻¹ .k⁻¹ × 298.15 k
n = 0.0003 atm. L / 24.5 atm. L . mol⁻¹
n = 1.2245 × 10⁻⁵ mol
Molar mass = mass / number of moles
Molar mass = 1.36g / 1.2245 × 10⁻⁵ mol
Molar mass = 1.111 × 10⁻⁵ g/mol
