def isobaric_expansion(V, dV_dT):
    """
    Calculate the isobaric coefficient of a thermal expansion, given its 
    molar volume at a certain `T` and `P`, and its derivative of molar volume
    with respect to `T`.

    .. math::
        \\beta = \\frac{1}{V}\\left(\\frac{\\partial V}{\\partial T} \\right)_P

    Parameters
    ----------
    V : float
        Molar volume at `T` and `P`, [m^3/mol]
    dV_dT : float
        Derivative of molar volume with respect to `T`, [m^3/mol/K]

    Returns
    -------
    beta : float
        Isobaric coefficient of a thermal expansion, [1/K]
        
    Notes
    -----
    For an ideal gas, this expression simplified to:
    
    .. math::
        \\beta = \\frac{1}{T}

    Examples
    --------
    Calculated for hexane from the PR EOS at 299 K and 1 MPa (liquid):
    
    >>> isobaric_expansion(0.000130229900873546, 1.58875261849113e-7)
    0.0012199599384121608

    References
    ----------
    .. [1] Poling, Bruce E. The Properties of Gases and Liquids. 5th edition.
       New York: McGraw-Hill Professional, 2000.
    """
    return dV_dT / V
