Calculate the amount of heat energy required to evaporate 25.7g of water at 100 degrees celcius. (molar heat of vaporization of liquid water= 4.07x10^4 j/mol)

5.82 ×10⁴ j

Explanation:

Given data:

Mass of water = 25.7 g

Amount of heat to evaporate it = ?

Molar heat of vaporization = 4.07×10⁴ j/mol

Solution:

First of all we will calculate the number of moles of water.

Number of moles = mass/ molar mass

Number of moles = 25.7 g/ 18 g/mol

Number of moles = 1.43 mol

Energy needed for one mole is 4.07×10⁴ j.

For 1.43 mol:

1.43 mol × 4.07×10⁴ j/ 1mol

5.82 ×10⁴ j

the correct answer is a

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer