Liquid ammonia (boiling point = -33.4°C)can be used as a refrigerant and heat transfer fluid.How much energy is needed to heat 25.0 g of NH₃(l)from -65.0°C to -12.0°C?

Question

Quizplus · Accepted Answer

To calculate the energy needed to heat the ammonia, we need to use the specific heat capacity formula:
q = m*c*ΔT
where q is the energy needed, m is the mass of the ammonia (25.0 g), c is the specific heat capacity of ammonia (4.7 J/(g°C)), and ΔT is the change in temperature (in this case, -12.0°C - (-65.0°C) = 53.0°C).

Plugging in the values:
q = (25.0 g)(4.7 J/(g°C))(53.0°C) = 6,242.5 J = 6.24 kJ (rounded to two decimal places)

Therefore, the best choice is C) 39 kJ, as it is the closest answer choice to our calculated value.

Liquid Ammonia (Boiling Point = -33