Short-Question

# Which of the following has the lowest critical temperature?

## Which of the following has the lowest critical temperature?

So, helium has the least temperature for liquefaction. Hence, option B is correct. Note: There is a limit to the temperature where the pressure has to be applied for the liquefaction of the gas. This temperature is known as critical temperature.

## What does critical volume mean?

the volume occupied by a certain mass, usually one gram molecule of a liquid or gaseous substance at its critical point: The numerical value of the critical volume depends upon the amount of gas under experiment. …

What affects critical temperature?

A The critical temperature depends on the strength of the intermolecular interactions that hold a substance together as a liquid. In N 2O, a slightly polar substance, weak dipole–dipole interactions and London dispersion forces are important.

### Which gas has highest critical temperature?

Water vapours i.e., H2O(g) molecules can be liquefied most easily due to presence of intermolecular hydrogen bonding. Therefore, they have maximum critical temperature .

### Which gas has lowest critical pressure?

Table of liquid–vapor critical temperature and pressure for selected substances

Substance Critical temperature
Helium −267.96 °C (5.19 K)
Hydrogen −239.95 °C (33.20 K)
Krypton −63.8 °C (209.3 K)
Methane (CH4) −82.3 °C (190.8 K)

Which refrigerant has highest critical temperature?

∴ Ammonia has the highest critical point pressure.

## How do you find critical volume?

The critical volume is the volume at Tc and Pc. In spite of the standard physical state at regular conditions, it is calculated as (Zc*R*Tc)/Pc, where Zc is the critical compressibility aspect, which ranges from 0.2 to 0.3. The value of Zc is often given in the literature; it can be estimated with low accuracy.

## What is the value of critical volume?

Therefore, critical volume is three times of van der Waals gas constant \$ b \$ which signifies the excluded volume or Co-volume. Hence option (A) is correct. And critical volume is given as \$ {V_C} = 3b \$ that is volume at critical temperature and critical pressure.

What is critical pressure critical temperature critical volume?

The volume of one mole of a gas volume liquefied at critical temperature is known as the critical volume (Vc) while the pressure required to liquefy the gas at critical temperature is called as the Critical pressure (pc).

### What happens above critical point?

Above the critical point there exists a state of matter that is continuously connected with (can be transformed without phase transition into) both the liquid and the gaseous state. It is called supercritical fluid.

### What is critical temperature critical volume and critical pressure?

When to use lower cutoff values for aortic stenosis?

Recent studies showed that lower cutoff values of aortic valve calcium score should be used in women (≥1200 AU) than in men (≥2000 AU) to identify true severe AS and predict mortality (Slide #2) 8, 9.

## When is AVR the most likely cause of symptoms?

In the ACC/AHA guidelines 3, a new class IIa indication of AVR was included for patients with paradoxical LF-LG AS if they are symptomatic, normotensive and the clinical, anatomical, and hemodynamic factors support the presence of a severe stenosis as the most likely cause of symptoms (Slide #1).

## What are the Critical Constants of Van der Waals?

From the critical constants like temperature, pressure, and volume formula of Van der Waals constants, b = V C /3 and a = 27 R 2 T C2 /64P C. Problem: The critical constants for water are 647 K, 22.09 MPa, and 0.0566 dm 3 mol -1. What is the value of a and b? Solution: T C = 647 K, P C = 22.09 Mpa = 22.09 × 10 3 kPa, V C = 0.0566 dm 3 mol -1.