Use the heat equation to calculate the energy, in joules, for each of the follow

Question

Use the heat equation to calculate the energy, in joules, for each of the following (see the table below): Table Specific Heats of Some Substances Substance Specific Heat (J/gC) Elements Aliminium, Al(s) 0.897 Copper, Cu(s) 0.385 Gold, Au(s) 0.129 Iron, Fe(s) 0.452 Silver, Ag(s) 0.235 Titanium, Ti(s) 0.523 Compounds Ammonia, NH3(g) 2.04 Ethanol, C2H5OH(l) 2.46 Sodium chloride, NaCl(s) 0.864 Water, H2O(l) 4.184 Water, H2O(s) 2.03

Part A

lost when 16.0 g of ethanol, C2H5OH, cools from 67.5 C to -45.0 C Express your answer using three significant figures.

B lost when 115 g of iron (Fe) cools from 117 C to 57 C Express your answer using two significant figures.

Explanation / Answer

Heat lost or gained = m*c*(T2-T1) joules

a) heat lost = 16*2.46*(-45-67.5) = -4428 Joules

b) heat lost = 115*0.452*(57-117) = -3118.8 Joules

here -ve sign indicates the loss of heat

Related Questions

Navigate

• Browse (All)
• Browse U
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.