Question

If you heated 100 g of water to 98 °c, how much heat must be released in order for the temperature of the water to decrease to 32 °c? is this process exothermic or endothermic? the specific heat of water is 4.184 j/g.˚c.

a) 20,000 J
b) 18,784 J
c) 22,720 J
d) 25,868 J

Answer 1

The heat that must be released to cool 100 g of water from 98 °C to 32 °C is 27,614.4 J, using the specific heat of water (4.184 J/g°C). The process is exothermic.

Step-by-step explanation:

To calculate the amount of heat that must be released for the temperature of 100 g of water to decrease from 98 °C to 32 °C, we use the formula q = mc∆T, where q is the heat exchanged, m is the mass of the water, c is the specific heat capacity of water, and ∆T is the change in temperature. The specific heat capacity of water is given as 4.184 J/g°C. The temperature change (∆T) is 98 °C - 32 °C = 66 °C.

Using the formula, we compute the heat released as follows:

q = m × c × ∆T
q = 100 g × 4.184 J/g°C × 66 °C
q = 27614.4 J

Thus, the amount of heat that must be released is 27,614.4 J, which is not one of the options provided, suggesting there may be an error in the question or options provided. This process is exothermic, as heat is released when the temperature of the water decreases.