Show the calculation of the final temperature of the mixture when a 40.5 gram sample of water at 85.7 degrees celcius is added to 36.8 gram sample of water at 26.3 degree celcius in a coffee cup calorimeter

Respuesta :

Answer:

The value of final temperature of the mixture  [tex]T_{3}[/tex] = 57.42 °c

Explanation:

Mass of first sample [tex]m_{1}[/tex] =  40.5 gram

Mass of second sample [tex]m_{2}[/tex] =  36.8 gram

Temperature of first sample [tex]T_{1}[/tex] = 85.7 °c

Temperature of second sample [tex]T_{2}[/tex] = 26.3 °c

The energy balance equation for the mixture is written as

[tex]m_{1}[/tex] [tex]T_{1}[/tex] + [tex]m_{2}[/tex] [tex]T_{2}[/tex] = [tex]m_{3}[/tex] [tex]T_{3}[/tex]  ---------- ( 1 )

Total mass [tex]m_{3}[/tex] = [tex]m_{1}[/tex] + [tex]m_{2}[/tex]

Put the values of [tex]m_{1}[/tex] & [tex]m_{2}[/tex]  in this equation we get,

⇒ [tex]m_{3}[/tex] = 40.5 + 36.8

⇒ [tex]m_{3}[/tex] =  77.3 gram -------- (2)

Put all the values of mass & temperature in equation 1 we get,

⇒ 40.5 × 85.7 + 36.8 × 26.3 = 77.3 × [tex]T_{3}[/tex]

⇒ 4438.69 = 77.3 × [tex]T_{3}[/tex]

[tex]T_{3}[/tex] = 57.42 °c

This is the value of final temperature of the mixture.