<

Calculate the amount of heat energy required to convert 55.0 g of water at 62.5°C to steam at 124.0°C. (Cwater = 4.18 J/g°C; Cst

Grace [21]

Answer:

= 135,647.65 Joules or 135.65 kJ

Explanation:

Heat require to raise the temperature of 55 g water from 62.5°C to 124.0°C will be calculated in steps;

Step 1; heat required to raise water from 62.5°C to 100 °C

Heat = 55 g × 4.18 J/g°C × (100 -62.5)

= 8,621.25 Joules

Step 2; Heat required to convert water to steam without change in temperature;

Heat = moles × Molar Latent heat of vaporization.

= (55g / 18 g/mol)× 4.07 ✕ 104 J/mol

= 12.436 × 10^4 Joules

Step 3: Heat required to raise the temperature of steam from 100°C to 124 °C.

Heat = mass × specific heat capacity × ΔT

= 55 g × 2.02 J/g°C × (124-100)

= 2,666.4 Joules

Therefore; total amount of heat required is;

= 8,621.25 J + 124360 J + 2,666.4 J

<u> = 135,647.65 Joules or 135.65 kJ</u>

4 0

3 years ago

Electron configuration of Mo

makkiz [27]

Answer:The computer writes electron configurations in the form, for Co for example, [Ar]3d(7)4s(2), which we would write [Ar]3d74s2

NOTE: Write electron configurations as they appear in the periodic table in the front of you text put 4f before 5d

Explanation:

3 0

3 years ago

an atom has a charge of -3 in its orbitals which statement must be true in order for this atom to have no net charge

NISA [10]

Answer:

The atom must lose its three extra electrons to make the atom over all neutral.

Explanation:

The three subatomic particles construct an atom electron, proton and neutron. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons.

If an atom have -3 charge it means three more electrons are added. In order to make the atom overall neutral three more electrons must be removed so that negative and positive charge becomes equal and cancel the effect of each other and make the atom neutral.

Electron:

The electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.

Symbol= e⁻

Mass= 9.10938356×10⁻³¹ Kg

It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.

Proton and neutron:

While neutron and proton are present inside the nucleus. Proton has positive charge while neutron is electrically neutral. Proton is discovered by Rutherford while neutron is discovered by James Chadwick in 1932.

Symbol of proton= P⁺

Symbol of neutron= n⁰

Mass of proton=1.672623×10⁻²⁷ Kg

Mass of neutron=1.674929×10⁻²⁷ Kg

7 0

3 years ago

What is the quantity of heat (in kJ) associated with cooling 185.5 g of water from 25.60°C to ice at -10.70°C?Heat Capacity of S

Cerrena [4.2K]

Taking into account the definition of calorimetry, sensible heat and latent heat, the amount of heat required is 37.88 kJ.

<h3>Calorimetry</h3>

Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.

<h3>Sensible heat</h3>

Sensible heat is defined as the amount of heat that a body absorbs or releases without any changes in its physical state (phase change).

<h3>Latent heat</h3>

Latent heat is defined as the energy required by a quantity of substance to change state.

When this change consists of changing from a solid to a liquid phase, it is called heat of fusion and when the change occurs from a liquid to a gaseous state, it is called heat of vaporization.

<u><em>25.60 °C to 0 °C</em></u>

First of all, you should know that the freezing point of water is 0°C. That is, at 0°C, water freezes and turns into ice.

So, you must lower the temperature from 25.60°C (in liquid state) to 0°C, in order to supply heat without changing state (sensible heat).

The amount of heat a body receives or transmits is determined by:

Q = c× m× ΔT

where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation.

In this case, you know:

c= Heat Capacity of Liquid= 4.184 $\frac{J}{gC}$
m= 185.5 g
ΔT= Tfinal - Tinitial= 0 °C - 25.60 °C= - 25.6 °C

Replacing:

Q1= 4.184 $\frac{J}{gC}$ × 185.5 g× (- 25.6 °C)

Solving:

<u><em>Change of state</em></u>

The heat Q that is necessary to provide for a mass m of a certain substance to change phase is equal to

Q = m×L

where L is called the latent heat of the substance and depends on the type of phase change.

In this case, you know:

n= 185.5 grams× $\frac{1mol}{18 grams}$ = 10.30 moles, where 18 $\frac{g}{mol}$ is the molar mass of water, that is, the amount of mass that a substance contains in one mole.