A 8.96-L sample of gas has a pressure of 1.86 atm and a temperature of 94 °C. The sample is allowed to expand to a volume of 11.5 L and is cooled to 43 °C. Calculate the new pressure of the gas, assuming that no gas escaped during the experiment.

Explanation:

Explanation:

All you have to do here is use the ideal gas law equation, which looks like this

P

V

=

n

R

T

−−−−−−−−−−

Here

P

is the pressure of the gas

V

is the volume it occupies

n

is the number of moles of gas present in the sample

R

is the universal gas constant, equal to

0.0821

atm L

mol K

T

is the absolute temperature of the gas

Rearrange the equation to solve for

T

P

V

=

n

R

T

⇒

T

=

P

V

n

R

Before plugging in your values, make sure that the units given to you match those used in the expression of the universal gas constant.

In this case, the volume is given in liters and the pressure in atmospheres, so you're good to go.

Plug in your values to find

T

=

3.10

atm

⋅

64.51

L

9.69

moles

⋅

0.0821

atm

⋅

L

mol

⋅

K

T

=

251 K

−−−−−−−−−

The answer is rounded to three

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.