AP Chemistrymediummcq1 pt
A coffee-cup calorimeter cup itself absorbs 50 J per °C. A reaction warms 150.0 g of water (c = 4.18 J/(g·°C)) by 4.00 °C. How much heat did the reaction release in total?
A.2.51 kJ
B.0.20 kJ
C.2.71 kJ
D.2.91 kJ
Explanation
Core Concept
The water absorbs q = 150.0 × 4.18 × 4.00 = 2508 J. The cup absorbs its own share: 50 J/°C × 4.00 °C = 200 J. The reaction released the total of both: 2508 + 200 = 2708 J, about 2.71 kJ. Careful calorimetry credits every heat-absorbing part of the apparatus, not just the water.
Correct Answer
C2.71 kJ
More Unit 6: Thermodynamics practice questions
- mediumA heating curve's plateau lengths differ because
- mediumWhich statement about work in chemistry is correct?
- mediumGiven: 2H₂ + O₂ → 2H₂O, ΔH = −571.6 kJ. What is ΔH per mole of water formed?
- mediumWhich statement about enthalpy of formation reactions is correct?
- mediumThe same amount of heat raises iron's temperature more than water's. Why?
Practice more AP Chemistry questions with full explanations
Practice Unit 6: Thermodynamics Questions →