Question

The heat of a reaction may be found with the equation q=mcΔT.

Answer 1

Answer:

B) -1551 kJ  

Explanation:

There are two heat flows in this question.

Heat released by engine + heat absorbed by water = 0

                   q₁                    +                      q₂                = 0

                   q₁                    +                   mCΔT            = 0

Data:

  m = 2.51 kg

  C = 3.41 J°C⁻¹g⁻¹

T_i =   23.8 °C

T_f =205     °C  

Calculations:

(a) ΔT

ΔT = 205 °C - 23.8 °C = 181.2 °C

(b) q₂

q₂ = mCΔT = 2510 g × 3.41 J·°C⁻¹g⁻¹ × 181.2 °C = 1.551× 10⁶ J = 1551 kJ

(c) q₁

q₁ + 1551 kJ = 0

q₁ = -1551 kJ