A series of equal-mass samples of the five materials listed in the table are brought from room temperature to 100. °C. Which sample required the least amount of energy (J) to reach the final temperature? Material Specific heat (J/g•°C) Al (aluminum) 0.903 Pyrex glass 0.75 Fe (iron) 0.449 Pb (lead) 0.128 water; H2O (l) 4.18

You have 8.99 g sample of an unknown salt (MM = 116.82 g/mol). It is dissolved in 150.00 g water in a coffee cup calorimeter. Before placing the sample in the water, the temperature of the salt and water is 23.72°C. After the salt has completely dissolved, the temperature of the solution is 28.54°C. What is the Mass inside calorimeter (g)? Change in Temp inside calorimeter (C)? How much Heat gained (J)? Total Heat? How many mols of the unknown salt? What is the change in empalthy?

A chemical reaction takes place inside a flask submerged in a water bath. The water bath contains 3.40kg of water at 32.4°C. During the reaction 60.8kJ 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 4.18·J·g−1K−1. Be sure your answer has the correct number of significant digits.

when 50.0 mL of 0.200 M NaOH is mixed with 50 mL of 0.200 M HCl in a coffee cup calorimeter, the temperature increases from 23.5 degrees C to 26.5 degrees C. Assuming that the density of the resulting solution is 1.00 g/mL and the specific heat capacity of the solution is 4.18 J/g degrees C, what is qrxn?

A student reacts 2.0 moles A and 4.0 moles of B in an insulated container. The reaction takes place in water (50.0 g), in a coffee cup. The water gains heat, raising its temperature 23.6°C (AT). Water has a specific heat capacity of 4.184 J/g C. A + 2B 3 C AHRXN = ? 1 a. Energy is absorbed by the water. What is qWATER? b. Energy is released by the reaction. What is qRXN? (this one is easy) c. How much heat per mol of A (or per 2 mol of B), by the reaction (AHRXN)? d. In another reaction, a student reacts 15.2 moles of B with excess A. What is the heat that comes out of his second reaction (qRXN-2)? use dimensional analysis +

A chemist carefully measures the amount of heat needed to raise the temperature of a 639.0 g sample of C,H,N from -8.7 °C to 6.7 °C. The experiment shows that 2.60 × 10* J of heat are needed. What can the chemist report for the molar heat capacity of C,H,N? Round your answer to 3 significant digits. - 1 ·K J• mol х10