Select true or false for each of the following.   Energy can be changed in form.    ΔT in units of K will always equal ΔT in units of ºC upon conversion.    When heat is released, the process is said to be exothermic.      Heat and temperature are the same thing.

Expressing amounts of energy in different energy units is necessary to solve many chemistry problems. For practice, complete the following table. The Joule (J) is the SI unit of energy. 1 calorie (cal) = 4.184 J J cal kJ 678 109 0.843

A chemical reaction takes place inside a flask submerged in a water bath. The water bath contains 4.70 kg of water at 38.7 °C. During the reaction 55.6 kJ of heat flows out of the flask and into the bath. Calculate the new temperature of the water bath. You can assume the specific heat capacity of water under these conditions is -1 4.18 J∙g¯¹·K¯¹. Be sure your answer has the correct number of significant digits. 心。 °℃ x10 S

If 30.5 g of LiBr are dissolved 350.0 g of water at 20.0 °C in an insulated container, a temperature change is observed. The Δ H of solution of LiBr is -48.8 kJ/mol. Assuming that the specific heat of the solution is 4.184 J/(g C) and that no heat is gained or lost by the container, what will be the final temperature of the solution?

A chemist carefully measures the amount of heat needed to raise the temperature of a 0.46 kg sample of a pure substance from 36.2 °C to 51.6 °C. The experiment shows that 33. kJ of heat are needed. What can the chemist report for the specific heat capacity of the substance? Round your answer to 2 significant digits.

1. A thermometer placed in a solution undergoing a chemical reaction indicates an increase in temperature as the reaction proceeds. Is this reaction endothermic or exothermic? Describe if heat energy is lost or gained from the reaction (the system) to the surroundings. What is the sign of the enthalpy change (AH) of this reaction? 2. A student performs a reaction and determines the enthalpy change (AH) to be 31.4 kJ. Will the temperature of the surrounding solution increase or decrease as a result of this chemical process? 3. If you hold 3 grams of ice in your hand at room temperature, your hand will become cold. a) Is the reaction H,O(s) – H,O(1) endothermic or exothermic? b) In which direction does heat flow?

A chemical reaction takes place inside a flask submerged in a water bath. The water bath contains  9.80kg  of water at  34.0°C . During the reaction  139.kJ  of heat flows out of the bath and into the flask. Calculate the new temperature of the water bath. You can assume the specific heat capacity of water under these conditions is  4.18·J·g−1K−1 . Be sure your answer has the correct number of significant digits. °C