Answer:
The heat given off by the burning Mg is 30.5 kJ/grams or 745.5 kJ/mol
Explanation:
<u>Step 1: </u>Data given
Mass of magnesium sample = 0.1149 grams
Molar mass of magnesium = 24.3 g/mol
bomb calorimeter that has a heat capacity of 1769 J/°C
Mass of water = 321 grams
Temperature change = 1.126 °C
Step 2: Calculated heat released
Q = (1769 J/°C * 1.126 °C) + (321 grams * 4.184 J/g°C * 1.126 °C)
Q = 3504.18 J =3.504 kJ
<u>Step 3:</u> Calculate the heat given off by the burning Mg, in kJ/g
3.504 kJ / 0.1149 grams = 30.5 kJ/grams
<u>Step 4:</u> Calculate moles of Magnesium
Moles of magnesium = mass magnesium / Molar mass magnesium
Moles magnesium = 0.1149 grams / 24.3 g/mol
Moles magnesium = 0.0047 moles
<u>Step 5:</u> Calculate the heat given off by the burning Mg, in kJ/mol
3.504 kJ / 0.0047 moles = 745.5 kJ/mol
The heat given off by the burning Mg is 30.5 kJ/grams or 745.5 kJ/mol
