Chemistry, 15.07.2019 02:30 maggie123456751

How much heat is required to vaporize 33.8 g of water at 100 ∘c?

Answers: 1

Show answers

Answers

Answer from: AquaNerd5706

The heat required to vaporize 33.8 g of water at ${\text{100 }}^\circ{\text{C}}$ is $\boxed{76.353{\text{2 kJ}}}$ .

Further explanation:

Properties are categorized into two types:

1. Intensive properties:

These properties depend on the nature of the substance and not on the size of the system. If the system is further divided into a number of subsystems, the values of intensive properties remain unchanged. Temperature, refractive index, molarity, concentration, pressure, and density are some of the examples of intensive properties.

2. Extensive properties:

These properties depend on the amount of the substance. These are additive in nature if a single system is divided into several subsystems. Mass, heat, enthalpy, volume, energy, size, weight, and length are some of the examples of extensive properties.

Heat of vaporization:

It is the amount of heat that is needed to convert a unit mass of the liquid into its vapors. It is also known as the enthalpy of vaporization or heat of evaporation. It is represented by $\Delta {H_{{\text{vap}}}}$ . Its unit is kJ/mol or J/mol.

The formula to calculate the moles of water is as follows:

${\text{Moles of water}}=\frac{{{\text{Given mass of water}}}}{{{\text{Molar mass of water}}}}$ …… (1)

The given mass of water is 33.8 g.

The molar mass of water is 18.01 g/mol.

Substitute these values in equation (1).

$\begin{aligned}{\text{Moles of water}}&=\left({{\text{33}}{\text{.8 g}}}\right)\left({\frac{{{\text{1 mol}}}}{{{\text{18}}{\text{.01 g}}}}}\right)\\&=1.87{\text{6 mol}}\\\end{aligned}$

The heat of vaporization of water at ${\text{100 }}^\circ{\text{C}}$ is 40.7 kJ/mol. This implies 40.7 kJ of energy is required to convert 1 mole of water into vapors. So the heat required to convert 1.876 moles of water is calculated as follows:

$\begin{aligned}{\text{Heat required}}&=\left( {{\text{1}}{\text{.876 mol}}}\right)\left({\frac{{{\text{40}}{\text{.7 kJ}}}}{{{\text{1 mol}}}}}\right)\\&=76.353{\text{2 kJ}}\\\end{aligned}$

Therefore the heat required to vaporize 33.8 g of water at ${\text{100 }}^\circ{\text{C}}$ is 76.3532 kJ.

Learn more:

1. Calculate the enthalpy change using Hess’s Law:

2. Find the enthalpy of decomposition of 1 mole of MgO:

Answer details:

Grade: Senior School

Subject: Chemistry

Chapter: Thermodynamics

Keywords: heat of vaporization, enthalpy of vaporization, heat of evaporation, 33.8 g, water, 40.7 kJ/mol, 76.3532 kJ, heat, intensive, extensive, molar mass of water, 18.01 g/mol, 1.876 mol.

Answer from: Quest

what is the question?

Answer from: Quest

remember that hf is only the energy of one photon. not two. not three. one. 1) 5.12 * 10^3 photons find the energy of one photon, then determine how many photons are needed to reach the sensitivity. e = hf = (6.626 * 10^-34 js)(5.95 * 10^19 hz) = 3.94247 * 10^-14 j per photon (2.02 * 10^-10 j) / (3.94247 * 10^-14 j/photon) = 5123.69149 photons round to three sig figs. 2) 5.77 * 10^-17 j energy of pulse = energy per photon * number of photons = hfn = (6.626 * 10^-34 js)(1.66 * 10^13 hz)(5250) = 5.774559 * 10^-17 j round to three sig figs. 3) 4.07 * 10^8 kj/mol 10^12 pm = 1 m c = fλ f = c/λ e = hf = hc/λ = [(6.626 * 10^-34 js)(3.00 * 10^8 m/s) / (2.94 * 10^-12 m)](1 kj/1000 j)(6.02 * 10^23 photons/mol) = 40702571.4 kj/mol round to three sig figs. 4) 9.94 * 10^-1 m e = hc/λ λ = hc / e = (6.626 * 10^-34 js)(3.00 * 10^8 m/s) / (2.00 * 10^-25 j) = 0.9939 m round to three sig figs. 5) 9.06 * 10^3 photons energy of pulse = energy per photon * number of photons number of photons = energy of pulse / energy per photon = energy of pulse / (hf) = (3.87 * 10^-13 j) / [(6.626 * 10^-34 js)(6.45 * 10^16 hz)] = 9055.23695 photons round to three sig figs. 6) 2.78 * 10^-15 j this is problem 1, except in reverse. sensitivity = minumum number of photons * energy per photon = (5930)(6.626 * 10^-34 js)(7.077 * 10^14 hz) = 2.78070758 × 10^-15 j round to three sig figs.

Another question on Chemistry

Chemistry, 21.06.2019 22:30

Each of the following compounds contains a metal that can exhibit more than one ionic charge. provide systematic names for each of these compounds. (a) cr(clo3)6 (b) mo(cn)6 (c) cr2(so3)3 (d) v(clo2)2 (e) v(cn)5 (f) os(clo2)4

Answers: 3

Answer

Chemistry, 22.06.2019 10:30

What woukd most likely be the transmittance at a 0.70 m solution of solute a? a) 7.6%b) 1.1%c)4.0%d)4.6%

Answers: 1

Answer

Chemistry, 22.06.2019 13:30

An animal cell loses the ability to convert energy stored in food to energy that the cell can use. which of the cell's organelles has stopped working? a.the mitochondria b.the nucleus c.the vacuoles d.the endoplasmic reticulum

Answers: 1

Answer

Chemistry, 22.06.2019 17:30