8. The density of a gas at 350 C is 0,087 g/L. Compute the density at STP.

0.20 g/L

Explanation:

Step 1: Calculate the molar mass of the gas (M)

At T = 350 °C = 623 K and P = 1 atm (we will assume this data), the density (ρ) of the gas is 0.087 g/L. We can calculate the molar mass of the gas using the following expression.

ρ = P × M/R × T

M = ρ × R × T/P

M = 0.087 g/L × (0.0821 atm.L/mol.K) × 623 K/1 atm = 4.5 g/mol

Step 2: Calculate the density of the gas at STP

At standard temperature (T = 273.15 K) and standard pressure (P = 1 atm), the density of the gas is:

ρ = P × M/R × T

ρ = 1 atm × 4.5 g/mol /(0.0821 atm.L/mol.K) × 273.15 K = 0.20 g/L

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.

i just learnt this recently but i need to look through my notes again