# How do you know when to use CP or CV?

## How do you know when to use CP or CV?

Use Cv when there’s constant volume. This is the specific heat when there’s constant volume. Use Cp when there’s constant pressure. This is the specific heat when there’s constant pressure.

## What is relation between CP and CV?

So, Cp represents the molar heat capacity, C when pressure is constant. In other words, Cv is the heat energy transfer between a system and its surrounding without any change in the volume of that system. Cv represents the molar heat capacity C when volume is constant.

**What is r in Mayers relation?**

Mayer’s formula is Cp – Cv = R. Here Cp is molar specific heat capacity of an ideal gas at constant pressure, Cv is its molar specific heat at constant volume and R is the gas constant. Specific heat capacity of a substance is defined as the heat supplied per unit mass of that substance per unit rise in temperature.

**What is r in thermodynamics?**

The ideal gas law is: pV = nRT, where n is the number of moles, and R is universal gas constant. The value of R depends on the units involved, but is usually stated with S.I. units as: R = 8.314 J/mol·K.

### What is the R in the ideal gas law?

The gas constant (also known as the molar gas constant, universal gas constant, or ideal gas constant) is denoted by the symbol R or R. It is equivalent to the Boltzmann constant, but expressed in units of energy per temperature increment per mole, i.e. the pressure–volume product, rather than energy per temperature …

### What is Regnault?

Regnault’s Law states that the specific heat capacity of a gas at constant pressure (Cp) and the specific heat capacity of a gas at constant volume (Cv) do not change with change in pressure and temperature.

**What is the R in the ideal gas law equation?**

R has the value 8.314 J/(K·mol) ≈ 2 cal/(K·mol), or 0.0821 l·atm/(mol·K).

**What are the 5 gas laws?**

The Gas Laws: Pressure Volume Temperature RelationshipsBoyle’s Law: The Pressure-Volume Law.Charles’ Law: The Temperature-Volume Law.Gay-Lussac’s Law: The Pressure Temperature Law.The Combined Gas Law.

#### What does Boyles law mean?

This empirical relation, formulated by the physicist Robert Boyle in 1662, states that the pressure (p) of a given quantity of gas varies inversely with its volume (v) at constant temperature; i.e., in equation form, pv = k, a constant. …

#### What is P in PV nRT?

In the formula P V = N R T {\displaystyle PV=NRT\,} : P is the pressure of the gas. In SI units, this is measured in Pascals, or Newtons of force per square meter of area. (“Standard atmospheric pressure at sea level” is about 101,000 Pascals, or 101 KiloPascals.