If you have 0.391 m 3 of water at 25.0 ∘ C and add 0.117 m 3 of water at 95.0 ∘ C , what is the final temperature of the mixture? Use 1000 kg/m 3 as the density of water at any temperature.

Respuesta :

In order to solve this problem, it is necessary to apply the concepts related to density, as a function of volume and mass, as well as the principle of calorimetry.

By definition we know that Density is given as a function of mass in a given volume, mathematically it can be expressed as

[tex]\rho = \frac{m}{V}[/tex]

Where,

m = mass

V = Volume

Re-arrange to find the respective mass at each state we have

[tex]m = \rho V[/tex]

For state 1 we have that the mass is

[tex]m_1 = (1000kg/m^3)(0.391m^3) = 391kg[/tex]

For state 2

[tex]m_2 = (1000kg/m^3)(0.117m^3) = 117kg[/tex]

Now from calorimetry we know that heat change is given under

[tex]Q = mc_p\Delta T[/tex]

For energy conservation then,

[tex]m_1c_p\Delta T = m_2c_p\Delta T[/tex]

Since the specific heat is the same for the fluid then,

[tex]m_1\Delta T = m_2\Delta T[/tex]

[tex](391) (T-25\°C) = (117) (95\°C-T)[/tex]

[tex]T = 41.12\°C[/tex]

Therefore the final temperature of the mixture will be 41.12°C