25.5 g of liquid Benzene (#C_6H_6#) loses 200 J of heat as it cools. What is the temperature decrease?

Cp(#C_6H_6#) = 1740 J/#kg*C#

1 Answer
Jun 10, 2018

Answer:

The temperature decrease is #~~"5"^@"C"#.

Explanation:

Use the equation:

#q=mcDeltaT#,

where:

#q# is energy, #m# is mass, #c# is specific heat capacity, and #DeltaT# is the change in temperature.

Known

#q="200 J"#

#m="25.5 g"="0.0255 kg"#
(Mass needs to be in kg due to the units used for the specific heat capacity.)

#c_"C6H6"=(1740"J")/("kg"*""^@"C")#

Unknown

#DeltaT#

Solution

Rearrange the equation to isolate #DeltaT#. Plug in the known values and solve.

#DeltaT=q/(m*c)#

#DeltaT=(200color(red)cancel(color(black)("J")))/((0.0255color(red)cancel(color(black)("kg")))xx(1740color(red)cancel(color(black)("J")))/(color(red)cancel(color(black)("kg"))*""^@"C"))="5"^@"C"# (rounded to one significant figure)

The temperature decrease is #~~"5"^@"C"#.