What is the molar mass of 4.23 g of an elemental gas in a 2.5L container at 282K and 1.4 atm?

27.98g/mol

Explanation:

Using ideal gas law equation;

PV = nRT

Where;

P = pressure (atm)

V = volume (L)

T = temperature (K)

n = number of moles (mol)

R = gas law constant (0.0821 Latm/molK)

According to the information given:

V = 2.5L

P = 1.4 atm

T = 282K

n = ?

Using PV = nRT

n = PV/RT

n = 1.4 × 2.5/0.0821 × 282

n = 3.5/23.1522

n = 0.151mol

Using the formula to calculate molar mass of the elemental gas:

mole = mass/molar mass

Molar mass = mass/mole

Molar mass = 4.23g ÷ 0.151mol

Molar mass = 27.98g/mol

first let us lay out the formula for potential

and kinetic energy:

pe = mgh

ke = (mv^2)/2

where: m=mass, v=velocity, g=gravitational

acceleration, h=height

calculating for mass using the known values of

pe:

340j = m (9.81 m/s^2) (50ft) (1m/3.28ft)

m = 2.27 kg

the law of conservation of energy states that

energy is neither created nor destroyed. therefore, the change in kinetic

energy from 50 ft to 35 ft would be equal to the change in potential energy

from 50 ft to 35 ft. however it would be opposite in signs since one is losing

while other is gaining.

ke(35ft) – ke(50ft) = - [ pe(35ft) – pe(50ft]

ke(50ft) = 0 since the brick is initially at rest

ke(35ft) = 340j - 2.27kg (9.81 m/s^2) (35ft)

(1m/3.28 ft)

ke(35ft)

= 102.38 j