A 4.70 g sample of a certain gas occupies 530. mL at STP. What mass of the same gas is present in a 1.15 L container at 40.5°C and 785 mm Hg?

A confusing problem.

Use PV = nRT and solve for n of the 4.70 g gas at STP, the convert n to molar mass. That is n = grams/molar msss. You know n and grams, solve for molar mass.

Then use PV = nRT again at the new conditions and solve for n in the new container at the new conditions. Then use n = grams/molar mass. You know molar mass and n, solve for grams.

5 mol/dm^3

To determine the mass of the gas present in the 1.15 L container at a given temperature and pressure, we can use the ideal gas law, which states:

PV = nRT

Where:
P = pressure (in atm)
V = volume (in L)
n = moles of gas
R = ideal gas constant (0.0821 L.atm/(mol.K))
T = temperature (in Kelvin)

First, let's convert the given values to appropriate units:

Given:
Volume (V) = 1.15 L
Temperature (T) = 40.5°C = (40.5 + 273.15) K
Pressure (P) = 785 mm Hg = (785/760) atm (converting from mm Hg to atm)

Now, we can rearrange the ideal gas law equation to solve for n (moles of gas):

n = PV / RT

Substituting the given values into the equation:

n = (785/760) atm * 1.15 L / (0.0821 L.atm/(mol.K) * (40.5 + 273.15) K

Now, we need to determine the molar mass of the gas. Using the ideal gas equation, we can rewrite it as:

n = (molar mass of gas) / (molar mass of 1 mole of gas)

Rearranging the equation to solve for the molar mass of gas:

molar mass of gas = n * (molar mass of 1 mole of gas)

Now, we can calculate the molar mass of the gas using the formula:

molar mass of gas = (n * molar mass of 1 mole of gas) / n

To find the mass of the gas, we can multiply the molar mass of the gas by the given volume at STP (530 mL) and convert it to grams:

mass of gas = (molar mass of gas) * (volume at STP) / (1 L / 1000 mL)

Substituting the calculated values into the equation, we can find the mass of the gas.