The table lists the specific heat values of several substances. Substance Specific heat (cal/g. C) An unknown substance has a mass of 11.9 g. The lead 0.031 temperature of the substance increases by 17.7 °C when 19 cal of heat is added to the substance. silver 0.058 copper 0.092 iron 0.107 aluminum 0.216 What is the most likely identity of the substance? water 1.000 copper water O lead

3. A 74.5 g piece of metal at 86.0°C is placed in 133 g of water at 21.0°C contained in a calorimeter. The metal and water come to the same temperature at 24.2°C. How much heat (in J) did the metal give up to the water? (Assume the specific heat of water is 4.18 J/g·°C across the temperature range.)  J What is the specific heat (in J/g·°C) of the metal?  J/g·°C 4. A 0.528 g sample of KCl is added to 51.7 g of water in a calorimeter. If the temperature decreases by 1.07°C, what is the approximate amount of heat (in J) involved in the dissolution of the KCl, assuming the heat capacity of the resulting solution is 4.18 J/g°C?  J Is the reaction exothermic or endothermic? exothermicendothermic  5. When 2.56 g of methane burns in oxygen, 128 kJ of heat is produced. What is the enthalpy of combustion (in kJ) per mole of methane under these conditions?  kJ/mol methane 6. Joseph Priestly prepared oxygen in 1774 by heating red mercury(II) oxide with sunlight focused through a lens. How much…

A 4.81 g sample of an unknown salt (MM = 116.82 g/mol) 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.   If 3.12 × 10³ J of heat was gained by the solution, what is the total heat for the dissolution reaction of the 4.81 g of salt?   How many moles of the unknown salt were used in the reaction ?     _______ J?

When substances are dissolved in water, they can absorb or release heat. Describe how you would use a calorimeter to determine the amount of heat required or released to when 10 grams of sugar is dissolved in 100 grams of water. Describe how you would calculate the heat absorbed or released by the sugar with the data you collect. (Do no perform any calculations.)

You are studying a chemical reaction. That reaction (the system) loses heat to the surroundings. O The reaction is endothermic The reaction is exothermic Not enough information has been provided

* 00 Σ In your own words, differentiate between an endothermic and exothermic reaction in one complete sentence. $ 4 9. Ə p alt

A 22.43 g sample of a substance is initially at 20.1° C. After absorbing 1603 J of heat, the temperature of the substance is 171.6° C. What is the specific heat (SH) of the substance?