8. Thermochemistry

When a 4.25g sample of solid ammonium

A coffee-cup calorimeter contains 130.0 g of water at 25.2 °C. A 124.0-g block of copper metal is heated to 100.4 °C by putting it in a beaker of boiling water. The specific heat of Cu(s) is 0.385 J/g·K. The Cu is added to the calorimeter, and after thermal equilibrium is reached, the final temperature of the system is measured. What is the final temperature of the water in the calorimeter?

In a constant-pressure calorimetry experiment, butane was burnt causing a temperature change of 25.5 K in 1200 g of water (specific heat capacity = 4.18 J/g⋅K). Calculate the heat change of the water. Give the answer to three significant figures.

In a coffee-cup calorimeter experiment, 10.00 g of a soluble ionic compound was added to the calorimeter containing 75.0 g H2O initially at 23.2°C. The final temperature of the solution was 31.8°C. What was the change in enthalpy (ΔH) for the dissolution of the compound?

In a constant-pressure calorimeter, 70.0 mL of 0.330 M Ba(OH)2 is mixed with 70.0 mL of 0.660 M HCl, causing the temperature to rise from 22.99 °C to 27.49 °C. Assuming the solution has the same density and specific heat as water, what is the enthalpy change (ΔH) of the reaction per mole of Ba(OH)2?

In a constant-pressure calorimetry experiment, a coffee-cup calorimeter containing 100 mL of water is used. The initial temperature of the calorimeter is 23.0 °C. If 8.20 g of CaCl2 is added to the calorimeter, what will be the final temperature of the solution, given that the enthalpy change for the dissolution of CaCl2 is -82.8 kJ/mol?

In a constant-pressure calorimetry experiment, a coffee-cup calorimeter containing 100 mL of water at an initial temperature of 23.0 °C is used. If 4.60 g of CaCl2 is added to the calorimeter, what will be the final temperature of the solution, assuming the dissolution of CaCl2 is an exothermic process?

You are experimentally determining the change in enthalpy when dissolving an ionic compound in water using a coffee-cup calorimeter. When you dissolve 38.28 g of the ionic compound (molar mass = 102 g/mol) in 369 g of water in a coffee-cup calorimeter, the temperature of the solution changes from 25.0°C to 28.5°C. Given that the specific heat capacity of water is 4.18 J/g°C, what is the change in enthalpy (ΔH) for the dissolution process?

What is the enthalpy change (ΔH) for the reaction when 200.0 mL of 0.100 M AgNO3 is mixed with 100.0 mL of 0.100 M NaCl in a coffee cup calorimeter, given that the temperature rises from 24.69°C to 25.16°C and the calorimeter has a heat capacity of 105.5 J/°C?

When 1.80 g of magnesium metal reacts with 200 mL of 6.00 M aqueous HCl, the temperature rises from 25.0 °C to 42.1 °C. Calculate ΔH in kilojoules for the reaction, assuming the heat capacity of the calorimeter is 776 J/°C. What is the value of ΔH?