Calculate the amount of heat needed to boil 65.8g of hexane (C6H14), beginning from a temperature of −3.3°C. Be sure your answer has a unit symbol and the correct number of significant digits.

To solve this problem, we need to know the specific heat capacity of hexane, its boiling point, and its heat of vaporization.

1. The specific heat capacity of hexane is 2.3 J/g°C, its boiling point is 69°C, and its heat of vaporization is 30.1 kJ/mol.

2. First, calculate the amount of heat needed to raise the temperature of hexane from -3.3°C to 69°C. Use the formula q = mcΔT, where m is the mass, c is the specific heat capacity, and ΔT is the change in temperature.

   q = (65.8 g)(2.3 J/g°C)(69°C - (-3.3°C)) = 10896.14 J

3. Next, calculate the amount of heat needed to boil hexane. First, convert the mass of hexane to moles using its molar mass (86.18 g/mol).

   n = 65.8 g / 86.18 g/mol = 0.763 mol

   Then, use the formula q = nΔHvap, where n is the number of moles and ΔHvap is the heat of vaporization.

   q = (0.763 mol)(30.1 kJ/mol) = 22.96 kJ = 22960 J

4. Finally, add the two amounts of heat to get the total heat needed.

   q_total = 10896.14 J + 22960 J = 33856.14 J

So, the amount of heat needed to boil 65.8g of hexane, beginning from a temperature of -3.3°C, is approximately 33856 J. This answer is rounded to five significant digits because the given values have at most five significant digits.