Determine the most likely identity of the unknown metal sample. Mass of empty beaker = 50.45 g Mass of beaker and water = 81.26 g Mass of water 30.81 g (represents a calculation rather than a direct measurement) Initial water temperature = 25.5 C Mass of metal = 54.02 g Initial metal temperature = 102.5 C Final water and metal mixture temperature = 36.0 C The specific heat capacity of water is 4184 J/kg C

Use the References to access important values if needed for this question Ethanol, C2H0, is most often blended with gasoline - usually as a 10 percent mix - to create a fuel called gasohol. Ethanol is a renewable resource and ethanol-blended fuels, like gasohol, appear to bum more efficiently in internal combustion engines. The combustion enthalpy of ethanol is 1366.9 kJ/mol The combustion enthalpy of 2-methylpentane, C6H14 is 4.157x103 kJ/mol. Calculate the energy released during the complete combustion of 382 g 2-methylpentane kJ Assuming the same efficiency, would 382 g ethanol provide more, less, or the same quantity of energy as 382 g 2-methylpentane? | Submit Answer Retry Entire Group 8 more group attempts remaining

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…

The specific heat capacity of silver is 0.2386 J/g °C. Assuming no loss of heat to the surroundings or to the calorimeter, determine the final temperature when 100.0 g of silver at 40.0°C is immersed in 60.0 g of water at 10.0°C.

When 3.8 g A are reacted with 8.5 g D,  according to the balanced chemical equation below, 33 kJ of energy are released.  Please calculate the enthalpy for this reaction when 3 moles of G are produced.  2A + 3D = 2Z + 3G  given molar masses: A = 141.8 g/mole D = 63.996 g/ mole Z = 4.032 g/ mole G = 56.028 g/ mole

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?

In a calorimeter, a 2.0 g sample of magnesium is burned to form MgO. In doing so, 25.5 kJ of energy are released. What is the Heat of Combustion in kJ/mol of magnesium? с 306.2 1.54 x 1025 0.0392 514 25.5

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?

Specific heat is the heat required to raise the temperature of 1 g of a substance by 1 °C. Based on this definition, what is the equation to calculate specific heat? Select one: heat O specific heat = %3D (mass x temperature change) temperature change specific heat = mass (heat x tempetature change) specific heat = mass temperature change O specific heat = (mass x heat)