Chloromethane, , arises from microbial fermentation and is found throughout the environment. It is also produced industrially, is used in the manufacture of various chemicals, and has been used as a topical anesthetic. How much energy is required to convert 74.0 g of liquid to a vapor at its boiling point, –24.09 °C? (The heat of vaporization of is 21.40 kJ/mol.) Energy required = kJ

31.36 KJ/mol

Explanation:

mass of the liquid = 74.0 g

heat of vaporization = 21.40 kJ/mol

constant boiling point temperature = 24.09 °C

heat required to vaporize 74.0g = heat of vaporization × mole

mole of Chloromethane = 74.0 g / 50.49 (g/mol) = 1.466 mol

energy required = 1.466 mol × 21.40 KJ/mol = 31.36 KJ/mol

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3

there are two significant figures.