When ice melts, it absorbs heat from its surroundings without increasing in temperature. This is because the energy is used to break the intermolecular bonds between the water molecules in the ice. The amount of energy required to melt one mole of a substance is called the heat of fusion.
The heat of fusion for water is 6.02 kJ/mol. This means that it takes 6.02 kJ of energy to melt one mole of ice. To calculate the amount of energy required to melt 70 g of ice, we need to convert the mass to moles:
n = m / M
where n is the number of moles, m is the mass, and M is the molar mass. The molar mass of water is 18.02 g/mol:
n = 70 g / 18.02 g/mol = 3.88 mol
The amount of energy required to melt 3.88 mol of ice is:
Q = n x ΔHfus
where Q is the amount of energy, ΔHfus is the heat of fusion. Substituting the values:
Q = 3.88 mol x 6.02 kJ/mol = 23.3 kJ
Therefore, the amount of energy that your body loses from eating (and melting) 70 g of ice is 23.3 kJ.