Question

Газосварщик использует для работы кислород из баллона объемом 40 л при температуре окружающего воздуха 300 К. В начале работы манометр показывал давление 2,3 МПа, а в конце работы 2,05 МПа. Какую массу газа израсходовал сварщик?

Answer 1

pV= m/M RT

(p1-p2) V= (m1-m2)/M RT

m1-m2= (p1-p2)V M/ RT

m1-m2= 0,25e6 4e-2 32e-3 / (300* 8,31)

m1-m2=0,128 кг

Answer 2

Gas Consumption Calculation for Welding

To calculate the mass of gas consumed by the welder, we can use the ideal gas law, which states:

PV = nRT

Where: - P is the pressure of the gas, - V is the volume of the gas, - n is the number of moles of the gas, - R is the ideal gas constant, and - T is the temperature of the gas in Kelvin.

Initial Conditions:

- Initial pressure (P1) = 2.3 MPa - Final pressure (P2) = 2.05 MPa - Volume of the gas (V) = 40 L - Temperature (T) = 300 K

First, we can calculate the initial and final number of moles of gas using the ideal gas law.

Calculating Initial and Final Number of Moles:

Using the ideal gas law, we can rearrange the formula to solve for the number of moles (n): n = PV / RT

For the initial conditions: n1 = (2.3 MPa * 40 L) / (8.314 J/(mol*K) * 300 K)

For the final conditions: n2 = (2.05 MPa * 40 L) / (8.314 J/(mol*K) * 300 K)

Gas Consumption:

The mass of the gas consumed can be calculated by finding the difference in the number of moles between the initial and final conditions and then multiplying by the molar mass of the gas.

Molar Mass of Oxygen (O2):

The molar mass of oxygen (O2) is approximately 32 g/mol.

Calculation:

Mass of gas consumed = (n1 - n2) * molar mass of O2

Let's calculate the mass of gas consumed using the given data.