7. Calculate the amount of energy required heat 100.g to the following: a. H2O(s) changes to H2O(l) at 0°C b. H2O(l) changes to H20 (s) at 0°C c. H2O(l) at 10°C changes to H2O(l) at 20°C​

Answers

Answer 1

a=b=33400 J

c=4180 J

Further explanation

Heat can be calculated using the formula:  

Q = mc∆T  

Q = heat, J  

m = mass, g  

c = specific heat, joules / g ° C  

∆T = temperature difference, ° C / K  

The heat to change the phase can be formulated :

Q = mLf (melting/freezing)

Q = mLv (vaporization/condensation)

Lf=latent heat of fusion

Lv=latent heat of vaporization

The heat of fusion for water at 0 °C : 334 J/g and the heat of vaporization at 100 °C : 2,230J/g

a. melting

[tex]\tt Q=100.334=33400~J[/tex]

b. freezing

[tex]\tt Q=100.334=33400~J[/tex]

c.raise the temperature(c water = 4.18 J/g C)

[tex]\tt Q=100\times 4.18\times (20-10)=4180~J[/tex]


Related Questions

A balloon originally had a volume of 4.39 L at 44C and a pressure of 729 torr  to what temperature must the balloon be cooled to reduce its volume to 3.78 L of the new pressure is at 1.0 atm

Answers

The new temperature : 11.56 °C

Further explanation

Boyle's law and Gay Lussac's law  

[tex]\tt \dfrac{P_1.V_1}{T_1}=\dfrac{P_2.V_2}{T_2}[/tex]

P1 = initial gas pressure (N/m² or Pa)  

V1 = initial gas volume (m³)  

P2 = final gas pressure  

V2 = final gas volume

T1 = initial gas temperature (K)  

T2 = final gas temperature  

V₁=4.39 L

T₁=44+273=317 K

P₁ = 729 torr = 0,959211 atm

V₂=3.78 L

P₂= 1 atm

[tex]\tt \dfrac{0.959211\times 4.39}{317}=\dfrac{1\times 3.78}{T_2}\\\\T_2=\dfrac{1\times 3.78\times 317}{0.959211\times 4.39}\\\\T_2=284.559~K=11.56~C[/tex]

What would the unit of measurement be for the density of a regular solid?

Answers

Answer:

SI unit: kg/m³

but g/cm³ is commonly used

Explanation:

Silver nitrate and magnesium chloride react according to the following equation:
2AgNO3(aq) + MgCl2(aq) — 2AgCl(s) + Mg(NO3)2(aq)
What volume (in ml) of 0.247M MgCl2(aq) is required to react with 63.2 mL of 0.192M AgNO3(aq)?

Answers

Answer:

V=24,3mL

Explanation:

1)n(AgNO3)=Cm*V=0.063l*0.192M=0.012

2)n(AgNO3)/2=n(MgCl2) => MgCl2=0.012/2=0.006

3)V(MgCl2)=n/Cm=0.006/0.247=0.0243L=24,3ml

How many grams of ZNO shoulbe added to 30gms of 10%ZNO to get 15%oint​

Answers

Mass of ZnO added=1.765 g

Further explanation:

Given

30gms of 10%ZnO(Zinc oxide)

15% ZnO

Required

mass of ZnO added

Solution

Amount of ZnO in 30 gms of 10% ZnO =3 gms

For 15% ZnO : x= ZnO added

New solution = 30+x = 15%, so the equation :

[tex]\tt \dfrac{3+x}{30+x}=15\%\\\\15\%(30+x)=3+x\\\\4.5+0.15x=3+x\\\\1.5=0.85x\\\\x=1.765~gms[/tex]

When scientists conduct investigations, they collaborate to support each other's research. What is the importance of scientists repeating the same experiment using the same steps?

It creates further questions to investigate, which creates more accurate results.
Having several trials that produce the same results is more accurate.
When multiple scientists repeat investigations, it allows them to investigate errors.
When scientists get more accurate results, the observations can be compared.

Answers

Answer:

b or c but most likely  it is c

Explanation:

B.   I just did this not lying a few minutes ago LOL

GL on the rest of your test!!!! :D

1.Outline the results of the Cathode ray tube?

Answers

Answer:

this showed that the cathode rays traveled in straight line

Carbon-14 has a half-life of 5715 years. It is used to determine the age of
ancient objects. If a sample today contains 0.060 mg of carbon-14, how much
carbon-14 will be present after 28,575?

Answers

The sample of Carbon-14 after 28,575 years=0.001875 mg

Further explanation

General formulas used in decay:  

[tex]\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{T/t\frac{1}{2} }}}[/tex]

T = duration of decay  

t 1/2 = half-life  

N₀ = the number of initial radioactive atoms  

Nt = the number of radioactive atoms left after decaying during T time  

Carbon-14 has a half-life of 5715 years, so t1/2=5715 years

A sample today contains 0.060 mg of carbon-14, so No=0.06 mg, then :

[tex]\tt Nt=0.06(\dfrac{1}{2})^{28575/5715}\\\\Nt=0.06(\dfrac{1}{2})^5\\\\Nt=0.001875~mg[/tex]

How many molecules are there in 560 grams of CoCl2?​

Answers

Answer:

25.89  × 10²³ molecules

Explanation:

Given data:

Mass of CoCl₂ = 560 g

Number of molecules present = ?

Solution:

Number of moles of CoCl₂:

Number of moles = mass/molar mass

Number of moles = 560 g/ 129.84 g/mol

Number of moles = 4.3 mol

Avogadro number:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.  The number 6.022 × 10²³ is called Avogadro number.

1 mole = 6.022 × 10²³ molecules

4.3 mol ×  6.022 × 10²³ molecules /1 mol

25.89  × 10²³ molecules

pls help 40 points!! Augie created this chart about the two kinds of waves.

A 2-column table with 3 rows titled 2 Kinds of Waves. The first column labeled Title 1 has entries the transfer energy is perpendicular to the direction of the wave motion, particles move up and down, particles move only slightly. The second column labeled Title 2 has entries the transfer direction is parallel to the direction of wave motion, particles move side to side, particles move only slightly.

Which best labels the chart?

Title 1 is “Longitudinal Waves,” and Title 2 is “Transverse Waves.”
Title 1 is “Transverse Waves,” and T

Answers

its b

i did the quiz and got it right it is b

Answer:

b

Explanation:

took test on edge

A chemical reaction occurs. The equation is: MgO ---> Mg + 0 This is a

combination reaction
decomposition reaction
double replacement reaction
single replacement reaction

Answers

Answer:

decomposition reaction

Explanation:

oxygen is broken down from magnesium oxide (mgo)

If 4.25 grams of copper were plated out in the reaction:
3Cu2+ + 2Al ---> 3Cu + 2Al3+
What mass of aluminum would have dissolved?

Please show all work!

Answers

Answer:

gravwfewtu

Explanation:

ushifelllf

The_______ and _____ are the main systems that move fluid throughout the body.

Answers

Answer:

circulatory system, lymphatic system

Explanation:

I just did the assigment and got it right.

Jean's mother lit a candle and placed it on his birthday cake. As they sang happy birthday, the wick burned, the wax
melted, the candle changed shape, and the air around the candle heated up. Which of the following is NOT an
example of a physical change?

Answers

Answer:

The wick burning

Explanation:

Which of the following is a simple definition of reduction?

A. the loss of electrons

B. the gain of electrons

C. an agent that oxidizes something

D. an agent that reduces something

The answer is B on Edg 2020

Answers

Answer:

B. the gain of electrons

Explanation:

An easy way to remember this concept is the pneumonic OIL RIG:

Oxidation is Loss (of electrons)

Reduction is Gain (of electrons)

B. The gain of electrons

Match the part of the wave to its description.
Crest
Wavelength
Trough
Amplitude
These are the correct answer your welcome ;)

Answers

Answer:

sgsgueiehéyegeysuegeteue2

Answer:

Explanation:

The answers you put are correct...

crest- A crest point on a wave is the maximum value of upward displacement within a cycle. A crest is a point on a surface wave where the displacement of the medium is at a maximum.

wavelength- In physics, the wavelength is the spatial period of a periodic wave the distance over which the wave's shape repeats. (how long the wave is)

trough- A trough is the opposite of a crest, so the minimum or lowest point in a cycle.

amplitude-  Amplitude, in physics, the maximum displacement or distance moved by a point on a vibrating body or wave measured from its equilibrium position. It is equal to one-half the length of the vibration path. ... Waves are generated by vibrating sources, their amplitude being proportional to the amplitude of the source.

Hope this helps! Have a great day!!  :D

what are the 4 quantum numbers of Kr?​

Answers

Answer:

2 8 18 8 those are the ones I believe.

The answer is 2, 8, 18, 8

Car battery energy that makes device work

Answers

engine is it ok ksndjsjja

Answer:

No it's not make device work

Explanation:

I think soo

Two ways water and ice are the same

Answers

Answer:

1- water is ice

2- ice is water

Explanation:

1- the water is just froze

2- the ice is just solid water

They are the same element just in different states.

What percentage of Canada's 2005 population was between the ages of 30 and 44?

Answers

ANSWER: 36,100,089 ........

Please help. Im not a very smart person

Answers

Either it’s, it is released when the reaction is complete or it is changed into atoms of carbon and oxygen during the reaction

last post as a troll lol, sorry but i need actual help this time.

Answers

All I have to say is karma

Answer:

Lol

Explanation:

lol

nah

How much heat is required to boil 78.5 gg of water at its boiling point?

Answers

Answer:

206 kj of heat is required to boil 78.5 kg of water at its boiling point

Which of these compounds has the highest boiling point?

Pentene

Chloropentane

2 Pentanone

Pentane

Answers

Answer:

2-Pentanone is the answer.

Explanation:

Phosphorus-32 has a half life of 14.3 days. How many days will it take for a
radioactive sample to decay to one-eighth its original size?

Answers

It will take 42.9 days

Further explanation

General formulas used in decay:  

[tex]\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{T/t\frac{1}{2} }}}[/tex]

T = duration of decay  

t 1/2 = half-life  

N₀ = the number of initial radioactive atoms  

Nt = the number of radioactive atoms left after decaying during T time  

t1/2=14.3 days

Nt/No=1/8

[tex]\tt Nt=No(\dfrac{1}{2})^{T/t1/2}\\\\\dfrac{Nt}{No}=\dfrac{1}{2}^{T/t1/2}\\\\\dfrac{1}{8}=\dfrac{1}{2}^{T/t1/2}\\\\(\dfrac{1}{2})^3=\dfrac{1}{2}^{T/t1/2}\\\\3=T/14.3\rightarrow T=42.9~days[/tex]

The nucleus is the cell as ​

Answers

A nucleus is an organelle found in the eukaryotic cells. Inside it's fully enclosed nuclear membrane, it contains the minority of the cell's genetic material. This material would be called DNA molecules.

Hope this helps! If not I'm so sorry. Have a lovely day

an apple with a mass of 0.95 kilograms hangs from a tree branch 3.0 meters above the ground. what is the potential energy of the apple?
0.28j
2.8j
28j
280j

Answers

Answer:

285 J

Explanation:

The potential energy of a body can be found by using the formula

PE = mgh

where

m is the mass

h is the height

g is the acceleration due to gravity which is 10 m/s²

From the question we have

PE = 0.95 × 10 × 30

We have the final answer as

285 J

Hope this helps you

Calcium hydroxide and hydrogen gas are produced by the reaction of calcium hydride and water

Answers

Explanation:

The reaction forms calcium hydroxide, Ca(OH)2 and hydrogen gas (H2). The calcium metal sinks in water and after an hour or so bubbles of hydrogen are evident, stuck to the surface of the metal.

Answer: B) calcium hydride + water -> calcium hydroxide + hydrogen

Explanation: B) on EDG

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