hiw much heat is needed to raise the temperature of 0.800 kg. ethyl alcohol form 15.0 celcius to its boiling point 78.3 celcius

160 celcius

see http://www.jiskha.com/display.cgi?id=1317927207

To find the amount of heat needed to raise the temperature of a substance, you can use the specific heat formula. The specific heat (C) is the amount of heat required to raise the temperature of one unit of mass (in this case, 1 kilogram) by one degree Celsius.

First, you need to determine the specific heat capacity of ethyl alcohol. The specific heat capacity of ethyl alcohol is approximately 2.44 J/g·°C. Since the mass is given in kilograms, we need to convert it to grams:

0.800 kg = 800 g

Next, we can use the formula:

Q = m * C * ΔT

Where:
Q is the amount of heat energy (in joules)
m is the mass of the substance (in grams)
C is the specific heat capacity (in joules per gram per Celsius degree)
ΔT is the change in temperature (in Celsius)

Let's calculate the amount of heat energy required:

Q = 800 g * 2.44 J/g·°C * (78.3°C - 15.0°C)

Q = 800 g * 2.44 J/g·°C * 63.3°C

Q ≈ 122,844 joules or 122.844 kJ (rounded to three decimal places)

Therefore, approximately 122.844 kJ of heat is needed to raise the temperature of 0.800 kg of ethyl alcohol from 15.0°C to its boiling point of 78.3°C.