Question

3. If the density of a gas at STP is .90g/L. What is the atomic mass and what elemental gas is it?

4. What gas is faster CO₂ or NO?
5. Under the same conditions of temperature and pressure, how many times faster will Ne effuse compared to sulfur dioxide?
6. If sulfur dioxide in problem 5 takes 25 seconds to effuse, how long will the neon take to go the same distance?
7. It takes He 4.58 times faster to effuse than an unknown gas. Find the atomic mass and what elemental gas it is?
8. He effuses 2.65 times faster than an unknown gas. Find the atomic mass and what elemental gas it is?
9. What volume is the balloon if 2.50g of CO₂, at 30.0°C and a pressure of 2.75atm?

Answer 1

The molar mass of a gas at STP can be calculated using the gas density at STP and the molar volume. The atomic mass of the gas depends on the specific gas being referred to. CO₂ is slower than NO. Ne effuses faster than sulfur dioxide by the square root of their molar mass ratio. The time it takes for neon to effuse the same distance as sulfur dioxide can be calculated using the effusion rate ratio and the time for sulfur dioxide to effuse. The molar mass and the elemental gas can be determined by comparing the effusion rate of helium to the unknown gas.

Step-by-step explanation:

3. The density of a gas at STP is determined by the molar mass and the volume of the gas. The molar mass can be calculated using the formula:

Molar Mass = (Density * Molar Volume)

Given the density of the gas at STP is 0.90 g/L, we can use this information and the molar volume of an ideal gas at STP (22.4 L/mol) to calculate the molar mass. Therefore, the atomic mass of the gas is 0.90 g/mol. Without additional information about the gas, we cannot determine the elemental gas.

4. The speed of a gas molecule can be determined by its molar mass. Generally, lighter molecules have higher speeds than heavier molecules at the same temperature. Given that CO₂ has a molar mass of 44 g/mol and NO has a molar mass of 30 g/mol, CO₂ is slower than NO.

5. The rate of effusion of two gases is inversely proportional to the square root of their molar masses. Since Ne has a molar mass of 20 g/mol and SO₂ has a molar mass of 64 g/mol, the effusion rate of Ne compared to SO₂ will be:

(sqrt(Mass SO₂) / sqrt(Mass Ne)) = (sqrt(64 g/mol) / sqrt(20 g/mol))

6. Given that sulfur dioxide takes 25 seconds to effuse, the time it takes for neon to effuse the same distance can be calculated using the equation:

Time Ne = (sqrt(Mass SO₂) / sqrt(Mass Ne)) * Time SO₂ = (sqrt(64 g/mol) / sqrt(20 g/mol)) * 25 seconds.

7. Given that Helium (He) effuses 4.58 times faster than an unknown gas, we can use the ratio of effusion rates to determine the molar mass of the unknown gas. The effusion rate ratio is given by:

Effusion Rate He / Effusion Rate Unknown = sqrt(Molar Mass Unknown) / sqrt(Molar Mass He) = 4.58.

8. Given that Helium (He) effuses 2.65 times faster than an unknown gas, we can use the ratio of effusion rates to determine the molar mass of the unknown gas. The effusion rate ratio is given by:

Effusion Rate He / Effusion Rate Unknown = sqrt(Molar Mass Unknown) / sqrt(Molar Mass He) = 2.65.

9. To find the volume of the balloon, we can use the ideal gas law equation: PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature. Rearranging the equation to solve for V, we get: V = (nRT) / P. Plugging in the given values, the volume of the balloon is calculated as follows:

V = (2.50 g / 44.01 g/mol) * (0.0821 L*atm/mol*K) * (30.0 + 273.15 K) / (2.75 atm).