If 1.22 grams of magnesium reacts with 100 ml of 6.02 M HCl solution. How much heat is evolved? Density of the HCl solution is 1.10 g/ml. Assume the specific heat of water 4.184 J/gC is the specific heat of the solution.
Mg + 2 HCl à MgCl2 + H2
I don't believe you have posted all of the information.
To calculate the amount of heat evolved in this reaction, we need to use the equation Q = mcΔT, where Q is the heat evolved, m is the mass, c is the specific heat, and ΔT is the change in temperature.
To calculate the mass of HCl solution, we multiply the volume (100 ml) by the density (1.10 g/ml) to get:
Mass of HCl solution = 100 ml * 1.10 g/ml = 110 g
Next, we need to calculate the moles of magnesium used in the reaction. We can use the molar mass of magnesium to convert grams to moles:
Molar mass of magnesium (Mg) = 24.31 g/mol
Moles of magnesium = 1.22 g / 24.31 g/mol = 0.0502 mol
According to the balanced equation, the mole ratio between magnesium and HCl is 1:2. Therefore, the moles of HCl used in the reaction can be calculated as:
Moles of HCl = 2 * (0.0502 mol) = 0.1004 mol
Now, we can calculate the heat evolved using the equation Q = mcΔT. The change in temperature (ΔT) can be assumed to be zero since there is no information given about a change in temperature. Assuming the specific heat of the solution is equal to the specific heat of water, c = 4.184 J/g°C:
Heat evolved (Q) = (110 g + 0.1004 mol * 36.46 g/mol) * 4.184 J/g°C * 0°C
Heat evolved (Q) = 110 g * 4.184 J/g°C * 0°C = 0 J
Therefore, no heat is evolved in this reaction.