At body temperature, 2404 J is required to evaporate 1 g of water. After vigorous exercise, a person feels chilly because the body is giving up heat to evaporate perspiration. A typical person perspires 25 mL of water after 20 minutes of exercise. How much body heat is used to evaporate this water

Answers

Answer 1

Answer: - 1.45 kJ

Explanation:

Using q  = m x C x (ΔT)

Given : m = 3.8 g  , C = 0.900 J/g°C,  = -(450-25)°C = -425°C  (Since final temperature is less than the initial, the sign is negative)

q = (3.8 g) x (0.900 J/goC) x ( -425 °C)

= -1453.5 J

= -1.45 kJ

Note that negative sign of q indicates that this much heat is released, when the metal cools down.


Related Questions

HELP PLS WILL GIVE BRAINLIEST AND THANKS

In a reaction chamber, 3.0mol of aluminum is mixed with 5.3mol Cl2 and reacts. The reaction is described by the following balanced chemical equation.

2Al + 3Cl2 ==> 2AlCl3

a)Identify the limiting reagent for the reaction.
b)Calculate the number of moles or products formed

Answers

Answer:

you have school on Sunday?

what are two basic properties of the gas phase

Answers

Answer:

It has no definite shape or volume.

i need help balancing the equation and number 4

Answers

Explanation:

I hope this helps answer your questions

3.0 Liters of gas at a pressure of 0.90 atm is compressed to 2.0 atm.
What is the new volume?

Answers

Answer:

5.5 L

Explanation:

Chromium (lII) sulphate reacts with potassium carbonate to form chromium (III) carbonate and potassium
sulphate.
Skeleton equation:

Answers

Cr2(SO4)3 + 3K2CO4 -> Cr2(CO4)3 + 3K2SO4

Answer:

Cr2(SO4)3+K2CO3---------------->Cr2(CO3)3+K2SO4

BALANCING

Cr2(SO4)3+3K2CO3------------------------->Cr2(CO3)+3K2SO4

Explanation:

Which lewis dot diagram shows an atom that needs 2 more electrons in its outermost shell?.

Answers

Answer:

Fluorine needs two more electrons on the outermost shell.

Explanation:

I'm in K12 too.

how many moles of o2 would be required to produce 4 mol h2o?

Answers

Hii there !

The reaction accompanying production of water in this case would be -

[tex]\green{ \underline { \boxed{ \sf{2H_2+O_2\longrightarrow 2H_2O}}}} [/tex]

Thus ,by observing the reaction, we can conclude that 2 mole of Hydrogen [tex](H_2 )[/tex]react with 1 mole of oxygen[tex](O_2)[/tex]to produce 2 mole of water [tex](H_2O)[/tex]

Now,

To produce 1 moles of water.

Moles of Oxygen[tex](O_2)[/tex] required [tex] = \frac{1}{2}[/tex] moles

Similarly,

To produce 4 moles of water.

[tex]\implies[/tex] Moles of Oxygen[tex](O_2)[/tex] required = [tex]\frac{1}{2}\times 4[/tex] moles

[tex]\implies[/tex] 2 moles

Hope it helps.

Distinguish between single and double replacement reactions and give an example of
each.

Answers

Answer:

i think this is right!

Explanation:

An example of a single replacement reaction occurs when potassium (K) reacts with water (H2O). A colorless solid compound named potassium hydroxide (KOH) forms, and hydrogen gas (H2) is set free. The equation for the reaction is: 2K + 2H2O → 2KOH + H.

An example of a double replacement reaction is the reaction between silver nitrate and sodium chloride in water. Both silver nitrate and sodium chloride are ionic compounds. Both reactants dissolve into their ions in aqueous solution.

What is due to acids formed when atmospheric and volcanic gases mix with water. question 2 options: chemical weathering mechanical weathering root-pry pedalfer

Answers

Chemical weathering formed is due to acids formation when atmospheric and volcanic gases mix with water.

What is chemical weathering?

Chemical weathering is a type of weathering that involved weakening and disintegration of rock by chemical reactions like acid reactions and so on. These reactions include oxidation, hydrolysis, and carbonation. These processes lead to formatiom or destruction of minerals, thus changing the nature of the rock's mineral composition.

Therefore, Chemical weathering is due to acids formed when atmospheric and volcanic gases mix with water.

Learn more about chemical weathering here.

https://brainly.com/question/974321

Which two organisms are most likely to be competitors?

chipmunk, cow
snake, hawk
snake, badger
chipmunk, badger

Answers

Chipmunk, badger I believe

Imagine that you are a leaf on a plant, and you realize that you are running low on supplies to do your job. You decide to text the roots to set up a delivery. Write a text message conversation between the leaf and the roots that discusses and arranges this delivery.
Be sure to answer these questions in your conversation:
• Which supplies is the leaf running out of? • What are the supplies needed to do? • How will the roots get the supplies from outside the plant? • How will the supplies get from the roots to the leaf?

Answers

The leaves of plants primarily serve to photosynthesize and require water conducted by the root to do so.

Water conduction by the root

As a leaf of a plant running low on supplies that the root is responsible for, what I will be needing is water.

Thus, I will have to send a text message to the root to supply me with water. The root will respond by asking its foot soldiers (the root hairs) to conduct water into the root.

Once water gets into the root, it enters special cells that are responsible for conducting water inside plants - the xylems. The root sends the water through the xylem and water travels from there to me - the leaf.

Once the water gets to me, I will use it in combination with inorganic carbon (carbon dioxide) to synthesize carbohydrates.

More on water conduction in plants can be found here: https://brainly.com/question/9533264

Which of the following formulas should be classified as an acid?
O Na₂SO4
O NaHCO3
O NaOH
O H₂SO4

Answers

Answer:

D) H₂SO4 is an acid

Explanation:

Please mark branliest

H[tex]_2[/tex]SO[tex]_4[/tex] is the chemical formula that should be classified as an acid. Therefore, the correct option is option D.

What is an acid?

Any substance that tastes acidic when dissolved in water, alters the colour of some indicators, reacts with the some metals to release hydrogen, reacts using bases to produce salts, and stimulates some chemical reactions is considered to be an acid. The inorganic chemicals referred to as being mineral acids sulfuric, nitrous, hydrochloric, or phosphoric acids are examples of acids.

The phenolic, sulfonic, and carboxylic acid groups of organic molecules. These chemicals contain one or maybe more hydrogen atoms, which are discharged into highly charged hydrogen ions when they are in solution. H[tex]_2[/tex]SO[tex]_4[/tex] is the chemical formula that should be classified as an acid.

Therefore, the correct option is option D.

To know more about an acid, here:

https://brainly.com/question/29796621

#SPJ7

The major product of the given reaction has the molecular formula c10h16o3. Draw its structure in the most stable tautomeric form.

Answers

Tautomers are isomers composed of the same atoms but with different electronic and molecular structures. The most stable tautomeric form is attached.

What is tautomery?

Tautomery is a special case of isomery produced by the change in the position of one or more atoms in the molecule. This change in position modifies the molecular electronic distribution, and hence, the molecular structure.

In solution, isomeres called tautomers are in equilibrium, and the constant interconversion is called tautomerization. Both molecules have the same type and quantity of atoms.

In the proposed example, the product has the molecular formula C₁₀H₁₆O₃. Isomeric molecules must have 6C, 16H, and 3O. However, the distribution of these atoms varies, leading to a change in the product molecule structure.

In the attached files you will find an example. You should check if this is the same example as yours.  

You can learn more about tautomeric forms at

https://brainly.com/question/13776462

https://brainly.com/question/6344293

https://brainly.com/question/15411301

https://brainly.com/question/25880668

Increasing the amplitude means you are increasing what of a wave?

Answers

The intensity of the sound or the sound is increasing

Cassiterite is an ore of a metal tin. What is an ore?

Answers

Answer:

Cassiterite is an ore of Sn.It is also called tinstone and has molecular formula of SnO

2 . It is heavy, metallic, hard tin dioxide that is the major ore of tin. It is colourless when pure, but brown or black when iron impurities are present.

What is the concentration in ppm of sodium fluoride in tap water that has been fluoridated by the addition of 32 mg of naf for every 20 kg of solution?.

Answers

ppm = mg/l = mg/kg

32 mg / 20 kg = 1.6 ppm

The concentration in ppm of sodium fluoride in tap water is 1.6 ppm.

What is ppm concentration?

ppm is  an abbreviation for parts per million. It can also be expressed as  milligrams per liter of a solution.It is a measurement which is equal to mass of a substance per unit volume .

One ppm is equivalent to the absolute fractional amount which is multiplied  by a million . It is a best way to describe smaller concentrations in a mixture such as that of gases,liquids or solids . It is a ratio of two quantities   which have  the same unit. In its full form ppm is expressed as one in a million part.

Depending on the substance being measured 1 ppm is expressed in many different ways, out of which preferred ways are microliters per liter , milligrams per liter and micrograms per liter.

For the given problem, concentration in ppm is found out as, since ppm is miiligrams  per liter the concentration is found out as follows:32 mg/20 kg (since kilograms  and liters  are  equivalent) =1.6 ppm

Thus, the  final concentration of sodium fluoride in tap water  which is fluorinated is 1.6 ppm.

Learn more about ppm concentration,here:

https://brainly.com/question/18090228

#SPJ2

write the name of high quatity of coal​

Answers

Answer:

Write the name of high quatity of coal​

Explanation:

If y’all can answer this I’ll give you’ll some extra points

From observing the reaction, what would you predict to be delta H and delta S for the hydration of CaO? Warning. This is a tricky question. To help you determine the correct answer, the chemical reaction involving CaO and water is written below. Remember to us the rules you learned about assigning the sign of delta S

2CaO(s) + H2O(l) —> 2Ca(OH)2(s)

Answers

Based on the nature ofbthe reaction, entropy (ΔS) increases while enthalpy (ΔH) decreases.

What are entropy and enthalpy changes?

Entropy changes, ΔS, refers to change in the degree of the disorderliness of a substance.

When substances become more random, entropy increases and vice versa.

For example, change of state from solid to liquid or gas results in increase in entropy.

Enthalpy changes, ΔH, refers to the changes in heat content of a substance, either a decrease or increase.

Enthalpy is negative when heat is lost and positive ehen heat is gained.

The enthalpy and entropy changes in the given reaction below is as follows:

2CaO(s) + H2O(l) —> 2Ca(OH)2(s)

Entropy, ΔS increases as the substance dissolves in water.

Enthalpy, ΔH, decreases as the substances gives off heat.

Therefore, in the given reaction entropy (ΔS) increases while enthalpy (ΔH) decreases.

Learn more about enthalpy and entropy at: https://brainly.com/question/1282789

Pumice is a volcanic rock that contains many trapped air bubbles. A 225- gram sample is occupied 236.6ml.
a. What is the density of pumice (answer is 0.951g/ml)

Answers

to find:

density of the pumice.

solution:

density= mass/ volume (d= m/v)

= 225/236.6

= 0.951g/ml

so, the density of pumice is 0.951g/ml.

[tex]{\boxed{{ formula :}}} [/tex]

[tex] →\bold{Density = \frac{mass}{volume} }[/tex]

[tex]{\boxed{{ Given :}}} [/tex]

[tex]→\bold{Mass = 225 g }[/tex]

[tex]→\bold{ Volume = 236.6 ml}[/tex]

[tex]{\boxed{{ Solution :}}} [/tex]

[tex]→\bold{Density = \frac{mass}{volume} }[/tex]

[tex]→\bold{ Density = \cancel{ \frac{225 g}{236.6 ml}} = 0.951 g/ml}[/tex]

The density of pumice is 0.951 g/ ml .

Which of the following is a structure of a cow?
O Possessing sharp teeth.
O Having hooved feet.
O Coming when called.
O None of the above.

Answers

Answer:

None of the above.

Explanation:

None of thesse things are part of the structure of a cow, cows have dished forhead 4 stomachs and angular body not sharp teeth comin when called or hooved feet.

HELPPPPP
A sample of gas contains 6 mol in a 22 L flask at 238 K. What is the pressure of the gas in atmospheres?

Answers

The pressure of the sample of gas with the given mol, volume and temperature is 5.33atm.

Ideal Gas Law

The Ideal gas law or general gas equation emphasizes on the state or behavior of a hypothetical ideal gas. It states that "pressure P times volume V is equal to moles times temperature and the universal gas constant. It is expressed;

PV = nRT

Where P is pressure, V is volume, n is the amount of substance, T is temperature and R is the ideal gas constant ( 0.08206 Latm/molK ).

Given the data in the question;

Amount of gas n = 6molVolume V = 22LTemperature T = 238KPressure P = ?

We substitute our values into the expression above to determine the pressure of the gas in atmospheres.

PV = nRT

P = nRT / V

P = ( 6mol × 0.08206Latm/molK × 238K ) / 22L

P = 117.18168Latm / 22L

P = 5.33atm

Therefore, the pressure of the sample of gas with the given mol, volume and temperature is 5.33atm.

Learn more about Ideal Gas Law here: brainly.com/question/4147359


The gas in a balloon occupies 2.25 L at 298 K and 300 kPa. At
what temperature will the balloon expand to 3.50L and 2.17 atm?

Answers

If a gas in a balloon occupies 2.25 L at 298 K and 300 kPa, the temperature at which the balloon expand to 3.50L and 2.17 atm is 345.23K.

How to calculate temperature?

The temperature of an ideal gas can be calculated using the following formula:

P1V1/T1 = P2V2/T2

Where;

P1 = initial pressureP2 = final pressureV1 = initial volumeV2 = final volumeT1 = initial temperatureT2 = final temperature

According to the information given in this question;

P1 = 300kpa = 2.96 atmP2 = 2.17 atmV1 = 2.25LV2 = 3.50LT1 = 298KT2 = ?

2.96 × 2.25/298 = 2.17 × 3.5/T2

0.022T2 = 7.595

T2 = 7.595 ÷ 0.022

T2 = 345.23K

Therefore, if a gas in a balloon occupies 2.25 L at 298 K and 300 kPa. the temperature at which the balloon expand to 3.50L and 2.17 atm is 345.23K.

Learn more about temperature at: https://brainly.com/question/11464844

Consider these equations:

2S (s) + 3O2 (g)→2SO3 (g), ΔH = −792 kJ
2S (s) + 2O2 (g)→2SO2 (g), ΔH = −594 kJ
2SO2 (g) + O2 (g)→2SO3 (g), ΔH =?

What is the missing ΔH?

a. −294 kJ
b. −198 kJ
c. +198 kJ
d. +294 kJ

Answers

The answer is a look at the solutions of G how they line up with each other we know so much about him

Answer: (B) −198 kJ.

explain any four effects caused due to exercise use chemical of chemical feritilizer on environment​

Answers

Excessive use of chemical fertilizers has led to several issues such as serious soil degradation, nitrogen leaching, soil compaction, reduction in soil organic matter, and loss of soil carbon.

Hope it helps :)

At the wavelengths included in Study 1, as the
wavelength of light increases, the reflectance of
Cyanide:
A.
increases only.
B.
decreases only.
C.
increases, then decreases.
D.
decreases, then increases.

Answers

Based on the research in Study 1, as the wavelength of light increases, the reflectance of Cyanide: C. increases, then decreases.

What is wavelength?

Wavelength is simply defined as the distance (in meters) between two (2) successive crests or troughs of a wave. Thus, wavelength refers to the horizontal distance between two adjacent crests or troughs of a wave.

Generally, there is a linear relationship between the wavelength of light and reflectance. Thus, as the wavelength of light increases, the reflectance of Cyanide in Study 1 increases, before it then decreases.

Find more information on wavelength here: brainly.com/question/23460034

Why is most space exploration
accomplished with spacecraft that do not have
crews on board?

Answers

Answer:

why is most space exploration accomplished with spacecraft that do not have crews on board? humans face many challenges in space. what is one advantage of using an orbiter to study objects in space? can be used for long periods of time.

complete and balance the following equation b. Br2 + Nacl​

Answers

Br2 + 2NaCl —> 2NaBr + Cl2

cacoH2+2NH4Cl-cacl2+2H2O+HN3
A. how many grame of cacl2 will be formed from the of
A20gm of cacoH2
B 40gm of NH4Cl

Answers

Answer:

a 63.428gm

b 41.5 gm

Explanation:

a

70 gm CaCOH2=111gm of CaCl2

40 gm =(111*40)/70

=63.428gm

b

107 gm of NH4Cl =111 gm of CaCl2

40 gm gives =(111*40)/107

=41.5 gm

Question 1 (8 points)
Name the following simple binary compounds.
1. NaBr =
2. KCl =
3. Mgo =
4. CaF2=
5. BaS =
6. Li20 =
7. NaF =
8. CS3N =

Answers

Answer:

Below

Explanation:

1. Sodium Bromide

2. Potassium Chloride

3. Magnesium Oxide

4. Calcium Fluoride

5. Barium Sulfide

6. Lithium Oxide

7. Sodium Fluoride

8. Cesium Nitride

_____is the force created when an object is physically pushed or pulled. *
1 point
A. applied force
B. friction
C. gravity
D. magnetism

Answers

Answer:

applied force .....I'm pretty sure

Answer:

A. Applied forces aka Contact forces

Explanation:

Thos force is created when you apply forces to an object as in a push/pull or other physical ways.


I hope it helps! Have a great day!

Anygays-

Other Questions
in the late 1700s, england was the leader of the? What was the government's part in the labor unions' fight to get workers'rights? A. The government sometimes agreed with workers.B. The government usually supported owners.C. The government always agreed with workers. D. The government always used military force. ToolsSave S7Which sentence from the passage is an example of an allusion?OA. Instead of relaxing in retirement in her 80s, she had become a rock star and a Shakespeare of the legalsystem.OB. These cases made a big difference for people suffering from inequality and unequal pay.OC. Her career as a lawyer was difficult at first because no law firms wanted to hire a female lawyer. Is it possible that someone could help me with this? (I tried to take the best picture a can) Find the median of the set of numbers below. 15, 16, 15, 7, 21, 18, 19, 20, 11 In the jeweler's workshop, the ruby would be clasped tightly into a settinflanked by diamonds.Based on word parts, what is the meaning of flanked in the sentence?the side of the body on a person or animalto be situated on each side of a possessionto guard or strengthen an item from the sideSHORT EXPLANATION the right or left side of a large body of people $9000 is invested at 8% compounded quarterly. In how many years will the account have grown to $14,500?Round your answer to the nearest tenth of a year Pls helpIn the previous three lessons, you have learned a lot about factoring. In this lesson, we will put it all together. Reply to the discussion by summarizing one thing that you have learned about the connections between finding the GCF of numbers, the distributive property, multiplying polynomials, and factoring. HELP ME OUT PLS!!!!!!! Which group was among the first to call for an end to slavery? A) American Indians, because they viewed the plight of slaves as similar to their own B) Quakers, because slavery contradicted their religious beliefs C) British loyalists, because Great Britain had ended the slave trade D) Puritans, because the New England economy did not rely on slavery. find the area of the circumference of a circle with diameter 7yd use the value 3.14 as pie -- What is the value of the expression 1\3x (5 + 7 x 4) - 10? 9 ft5 ft55 ft12 ft7 ft14 ft please help with this Question please I need it for homework Question # 7Fill in the BlankComplete the following sentence.There are four major types of cancer: ______, carcinoma, leukemia, and sarcoma. The difference between the supplement of an angle and twice its complement is 28, find the measure of the supplement of the angle. PLSS HELP!! FIRST ANSWER GETS BRAINLIEST!!!!At a baseball game, the Rebelos orrdered 2 hot dogs and 3 cheese burgers and paid $20.00. The Caines ordered 2 hot dogs and 5 cheeseburgers and paid $29.00. What is the cost of one cheeseburger? A key significance of churchills purpose in the excerpt was that it helped prompt the united states to. Finish the sentence below with the most likely answer:My shadow's the only one that walks beside me. My _____ heart's the only thing that's beating.A. ShallowB. EmptyC. SadD. Broken What is the most likely reason why the United States would send military aid to countries controlled by dictators? to help bring an end to protests to stop a larger enemy or threat to allow dictators to gain control to take control of the government If you are going to the water park and they said that you need pay a ticket and there is 11 people and it is 20 dollars for one ticket how many dollars would you have to pay for 4. Alex wants to measure lengths of rope for a knot-tying activity at camp What is the best customary unit of measurement for Alex to use to measure the rope? Why?