3.1.2.3 The ideal gas equation

Two sealed flasks with the same volume are left side by side.

Flask A contains 4.0 × 10⁻³ mol of methane.

Flask B contains 340 mg of a different gas.

Both gases are at the same temperature and pressure.

Which gas could be in Flask B?

• CH₂Cl₂

• HBr

• Kr

• PF₃

A 385 cm³ sample of carbon dioxide at 100 kPa and 25 °C was mixed with 2.89 × 10⁻² mol of argon. The gas constant, R = 8.31 J K⁻¹ mol⁻¹

What is the mole fraction of carbon dioxide in the mixture?

• 0.35

• 0.46

• 0.54

• 0.65

A student is provided with 5.00 cm³ of 1.00 mol dm⁻³ ammonia solution. The student was asked to prepare an ammonia solution with a concentration of 0.050 mol dm⁻³

What volume of water should the student add?

• 45.0 cm³

• 95.0 cm³

• 100 cm³

• 995 cm³

130 cm³ of oxygen and 40 cm³ of nitrogen, each at 298 K and 100 kPa, were placed into an evacuated flask of volume 0.50 dm³.

What is the pressure of the gas mixture in the flask at 298 K?

• 294 kPa

• 68.0 kPa

• 34.0 kPa

• 13.7 kPa

Which of these samples of gas contains the largest number of molecules?

The gas constant R = 8.31 J K^–1 mol^–1.

• 5.0 × 10^–4 m³ at 1.0 × 10⁶ Pa and 300 K

• 4.0 × 10^–3 m³ at 2.0 × 10⁵ Pa and 400 K

• 3.0 × 10¹ dm³ at 3.0 × 10⁴ Pa and 500 K

• 2.0 × 10² dm³ at 4.0 × 10³ Pa and 600 K

A sample of 2.18 g of oxygen gas has a volume of 1870 cm³ at a pressure of 101 kPa.

What is the temperature of the gas? The gas constant is R = 8.31 J K^–1 mol^–1.

• 167 K

• 334 K

• 668 K

• 334 000 K

In an experiment to identify a Group 2 metal (X), 0.102 g of X reacts with an excess of aqueous hydrochloric acid according to the following equation.

X + 2HCl --> XCl₂ + H₂

The volume of hydrogen gas given off is 65 cm³ at 99 kPa pressure and 303 K.

The gas constant is R = 8.31 J K^–1 mol^–1.

Which is X?

• Barium

• Calcium

• Magnesium

• Strontium

Tags

NGSS.HS-PS1-2

30 cm³ of xenon are mixed with 20 cm³ of fluorine. The gases react according to the following equation. Assume that the temperature and pressure remain constant.

Xe(g) + F₂(g) → XeF₂(g)

What is the final volume of gas after the reaction is complete?

• 50 cm³

• 40 cm³

• 30 cm³

• 20 cm³

2 mol of ideal gas X are stored in a flask of fixed volume.

Which of the following changes would lead to the greatest increase in pressure inside the flask?

• Increasing the temperature from 20 °C to 200 °C

• Adding another 1 mol of gas X into the flask at fixed temperature

• Adding 0.5 mol of argon gas and increasing the temperature from 20 °C to 150 °C

• Removing 0.5 mol of gas X and increasing the temperature from 20 °C to 300 °C

Tags

NGSS.HS-PS3-2

NGSS.HS-PS3-4

The removal of silicon dioxide with limestone in the Blast Furnace can be represented by the following equation.

CaCO₃(s) + SiO₂(s) → CaSiO₃(l) + CO₂(g)

The volume of carbon dioxide, measured at 298 K and 1.01 × 10⁵ Pa, formed in this reaction during the removal of 1.00 tonne (1000 kg) of silicon dioxide is

• 24.5 dm³

• 408 dm³

• 24.5 m³

• 408 m³