Question

1. A 15.00 gram sample of ammonium chloride was dissolved in 100.00 grams of water. How much heat is produced by the dissolution (absorbed from the solution) if the solution temperature goes from 22.0 *C to 1.0 *C. The specific heat of the solution is 4.18 J/g*C

2. 300.0 mL of a 2.500 M Solution X was mixed with 300.0 mL of a 2.500 M Solution Y in a calorimeter. Both of the solutions were at the same temperature initially. Determine the heat of neutralization (kj/mole) if the temperature goes from 12.0 *C to 29.0 *C. Assume a molar ratio of 1:1. The specific heat of the solution is 4.281 J/ g*C. The density of the mixture is 1.050 g/mL.

3. Sketch a crude time-temperature graph for an endothermic reaction

4. Why, on an exothermic time-temperature graph, does the temperature eventually fall?

Answer 1

NOTE-

Questions that are posted on the boards all differ in length and complexity. They often include subparts- like a, b, c, d, i, ii. In order to make the best use of your valuable answering time, please follow the following protocol for questions with many subparts:

• than 1 question: answer the first question
  • Unless a student explicitly mentions a question to answer- for instance, “answer the third question”. In this case, the question requested should be the one answered.
• More than 1 question, with subparts: answer the first 4 subparts
  • Regardless of the number of questions, answer the first 4 subparts
  • For instance: 1a, 1b, 2a, 2b
  • Unless a student explicitly mentions a different question to answer. In that case, answer the requested question.
• Less than 3 subparts: answer all parts
• More than 3 subparts: answer the first 4 subparts
  • e.g. subparts a, b, c, d