how many millilitres of water at 23 degree centigrade with the density of 1.00 g / ml must be mixed with 180 ml (about 6 oz) of coffee at 95 degree centigrade so that the resulting combination will have a temperature of 60 degree centigrade assume that coffee and water have the same density and the same specific heat

Respuesta :

Answer:

141.7475 milliliters of water must be added.

Explanation:

Heat gained by water will be equal to heat loss by the coffee solution.

[tex]-Q_1=Q_2[/tex]

Mass of water = [tex]m_1[/tex]

Specific heat capacity of water= [tex]c_1=c [/tex]

Initial temperature of the water= [tex]T_1=23 ^oC[/tex]

Final temperature of water coffee solution= [tex]T_2[/tex]= 60 °C

[tex]Q_1=m_1c\times (T-T_1)[/tex]

Mass of coffee solution= [tex]m_2=6 oz= 170.097 g[/tex]

1 oz = 28.3495 grams

Specific heat capacity of coffee= [tex]c_2=c_1=c [/tex]

Initial temperature of the coffee solution= [tex]T_3=95^oC[/tex]

Final temperature of water coffee solution= [tex]T_2[/tex]=T=60 °C

[tex]Q_2=m_2c\times (T-T_3)[/tex]

[tex]-Q_1=Q_2[/tex]

[tex]-(m_1c_\times (T-T_1))=m_2c_\times (T-T_3)[/tex]

On substituting all values:

we get, [tex]m_1 = 141.7475 g[/tex]

Density of the water = 1.00 g/mL

Volume of the water =[tex]\frac{141.7475 g}{1.00 g/mL}=141.7475 mL[/tex]

141.7475 milliliters of water must be added.