Question

1л газа при нормальных условиях имеет массу 0.759 г. определить молярную массу

Answer 1

N(газа)=V/Vm=1/22.4=0.04464 моль
М=m/n=0.759/0.04464=17 г/моль

Answer 2

Calculation of Molar Mass

To determine the molar mass of a substance, we need to know the mass of one mole of that substance. In this case, we are given that 1 liter (1 L) of gas at normal conditions has a mass of 0.759 grams (0.759 g). We can use this information to calculate the molar mass.

The molar mass is defined as the mass of one mole of a substance and is expressed in grams per mole (g/mol). To calculate the molar mass, we need to convert the given mass of gas to moles.

To convert grams to moles, we can use the formula:

moles = mass / molar mass

Rearranging the formula, we can solve for the molar mass:

molar mass = mass / moles

In this case, we are given the mass of gas (0.759 g) and we need to find the molar mass. However, we are not given the number of moles directly. We can use the ideal gas law to find the number of moles.

The ideal gas law is given by the equation:

PV = nRT

Where: - P is the pressure of the gas - V is the volume of the gas - n is the number of moles of gas - R is the ideal gas constant - T is the temperature of the gas

Since we are given the volume of gas (1 L) and the mass of gas (0.759 g), we can assume that the pressure and temperature are at normal conditions. Therefore, we can use the ideal gas law to find the number of moles.

Now, let's calculate the molar mass using the given information.

Calculation Steps:

1. Convert the given mass of gas to moles using the ideal gas law. 2. Calculate the molar mass using the formula molar mass = mass / moles.

Calculation:

Given: - Mass of gas = 0.759 g - Volume of gas = 1 L

Step 1: Convert mass to moles using the ideal gas law.

We need to find the number of moles (n) using the ideal gas law equation:

PV = nRT

Since the pressure (P), volume (V), and temperature (T) are at normal conditions, we can assume: - P = 1 atm - V = 1 L - R = 0.0821 L·atm/(mol·K) (ideal gas constant) - T = 273.15 K (standard temperature)

Substituting the values into the equation, we can solve for n:

1 atm * 1 L = n * 0.0821 L·atm/(mol·K) * 273.15 K

Simplifying the equation:

1 = n * 22.414

n = 1 / 22.414

n ≈ 0.0446 moles

Step 2: Calculate the molar mass using the formula molar mass = mass / moles.

Substituting the values into the equation:

molar mass = 0.759 g / 0.0446 moles

molar mass ≈ 17.02 g/mol

Therefore, the molar mass of the gas is approximately 17.02 g/mol.

Please note that the given information is limited, and the calculation assumes ideal gas behavior and normal conditions.