Calculate the number of kilojoules to warm 125 g of iron from 23.5°c to 78.0°c.

3065.63 J = 3.066 kJ.

Explanation:

Q = m.c.ΔT,

where, Q is the amount of heat needed to warm Fe (Q = ??? J).

m is the mass of Fe (m = 125.0 g).

c is the specific heat capacity of Fe (c = 0.45 J/g.°C).  

ΔT is the difference in T (ΔT = final temperature - initial temperature = 78.0°C - 23.5°C = 54.5°C).

∴ Q = m.c.ΔT = (125.0 g)(0.45 J/g.°C)(54.5°C) = 3065.63 J = 3.066 kJ.

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.

warm front forms when a moist, warm air mass slides up and over a cold air mass. as the warm air mass rises, it condenses into a broad area of clouds. a warm front brings gentle rain or light snow, followed by warmer, milder weather.

hope i !