Answer to Question #196771 in General Chemistry for cameron iles

Question

What is the mass of brass that requires 5200J to heat it from 23 C to 100 C? The specific heat of brass is 0.380 J/g*C.

Answer 1

Solution:

q = m × C × ΔT

q = m × C × (T_f - T_i),

where:

q = amount of heat energy gained or lost by substance (J)

m = mass of sample (g)

C = specific heat capacity (J °C^-1 g^-1)

T_f = final temperature (°C)

T_i = initial temperature (°C)

 

q = 5200 J

m = unknown

C = 0.380 J °C^-1 g^-1

T_f = 100°C

T_i = 23°C

Thus:

(5200 J) = m × (0.380 J °C^-1 g^-1) × (100 - 23)°C

(5200 J) = m × (29.26 J g^-1)

m = (5200 J) / (29.26 J g^-1) = 177.717 g = 177.72 g

m = 177.72 g

Answer: The mass of brass is 177.72 g