Final answer:
To find how many grams of methylamine are needed to heat 387 g of water from 22.0°C to 55.0°C, calculate the total energy required using the specific heat of water, then relate this energy to the enthalpy of combustion for methylamine.
Step-by-step explanation:
To determine how many grams of methylamine must be combusted to raise the temperature of 387 g of water from 22.0°C to 55.0°C, we can apply the concept of calorimetry and use the specific heat capacity of water. To calculate this, we use the formula q = m * c * ΔT, where q is the heat absorbed or released, m is the mass of the water in grams, c is the specific heat capacity of water (4.184 J/g°C), and ΔT is the change in temperature in degrees Celsius.
First, we calculate the amount of energy required to heat the water:
q = 387 g * 4.184 J/g°C * (55.0°C - 22.0°C).
Next, we use the enthalpy of combustion of methylamine obtained from standard thermochemical tables to determine the mass of methylamine needed.