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4 years ago

What is the amount of heat absorbed when the temperature of 75 grams of water increases from 20.°C to 35°C

Chemistry

2 answers:

SOVA2 [1]4 years ago

5 0

Answer:

4702.5 J/g*k

Explanation:

Depending on if it is water as a solid liquid or gas. I used water as a liquid when I solved it. J=(75g)(4.18 J/g*k)(15K)

Alenkasestr [34]4 years ago

4 0

Answer:

4.704625 kJ (or 4704.625 J) is the amount of heat absorbed when the temperature of 75 grams of water increases from 20.°C to 35°C.

Explanation:

The measurement and calculation of the amounts of heat exchanged by a body or system is called calorimetry.

In this way, there is a direct proportionality relationship between heat and temperature. The constant of proportionality depends on the substance that constitutes the body as its mass, and the product of specific heat is produced by the body's mass. So, the equation that allows to calculate heat exchanges is:

Q = c * m * T

Where Q is the heat exchanged for a body of mass m, constituted by a specific heat substance c and where T is the temperature variation.

In this case:

The specific heat capacity (c) of water is 4,181 J / g°C
m=75 g
T=35°C - 20°C ⇒ T= 15°C

Then:

$Q= 4.181 \frac{J}{g C} * 75 g *15 C$

Q≅4704.625 J

Being 1 kJ = 1000 J:

Q=4.704625 kJ

Finally, 4.704625 kJ (or 4704.625 J) is the amount of heat absorbed when the temperature of 75 grams of water increases from 20.°C to 35°C

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Karolina [17]

Answer:

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The concentration of NH₃ at equilibrium is 0.295 M. Then,

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3 years ago

How many phase rule variables must be specified to fix the thermodynamic state of each of the following systems? Show how you de

Murrr4er [49]

Answer: (i) F = 2

(ii) F = 3

(iii) F = 2

Explanation:

We would be applying the famous Gibbs Phase Rule to explaining this problem;

By applying the formula;

F+P = C +2

Where P = this represent the phase

F = this is called the degree of freedom

C = this represent the component in the system

Ok let us begin;

(i). from this we can see that there are 2 components i.e. (water + ethanol) and the phase in question is a vapor phase + liquid phase.

So from the formula;

F = C-P+2

F = 2 – 2 + 2 = 2

Therefore, F = 2.

(ii). Also, from the statement, we can figure there are 3 components, while the phases are two like the previous one above, i.e. liquid + vapor

F = 3 – 2 + 2 = 5 – 2 = 3

F = 3

(iii). From this statement, we can figure there are 3 components, and the phases are 3 i.e. (2 liquid phases + 1 vapor phase)

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F = 3 – 3 + 2 = 0 + 2

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6 0

4 years ago

Two atoms of the same substance wi the different numbers of neutrons are called what

sattari [20]

They are called ISOTOPES.
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4 0

3 years ago

PLEASE HELP ME ASAPP!!

aliina [53]

Conduction-

putting an icepack on injury

grabbing a warm coffee mug

burning yourself by touching boiling water

the handle of a pot being to hot to touch

Convection-

heat from a fire to warm hands

warm water rising to the surface of of the ocean etc.

warm air rising off pavement

an oven that cooks by cycling warm air through the bottom and out the top

Radiation-

cooking popcorn using microwave

heat from the sun hitting a solar panel

( i havent done science in a while cuz im homeschooled but i think most of these are correct)

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7 0

3 years ago

Under standard-state conditions, which of the following species is the best reducing agent? a. Ag+ b. Pb c. H2 d. Ag e. Mg2+

eimsori [14]

Answer: The correct answer is Option b.

Explanation:

Reducing agents are defined as the agents which help the other substance to get reduced and itself gets oxidized. They undergo oxidation reaction.

$X\rightarrow X^{n+}+ne^-$

For determination of reducing agents, we will look at the oxidation potentials of the substance. Oxidation potentials can be determined by reversing the standard reduction potentials.

For the given options:

Option a: $Ag^+$

This ion cannot be further oxidized because +1 is the most stable oxidation state of silver.

Option b: $Pb$

This metal can easily get oxidized to $Pb^{2+}$ ion and the standard oxidation potential for this is 0.13 V

$Pb\rightarrow Pb^{2+}+2e^-;E^o_{(Pb/Pb^{2+})}=+0.13V$

Option c: $H_2$

This metal can easily get oxidized to $H^{+}$ ion and the standard oxidation potential for this is 0.0 V

$H_2\rightarrow 2H^++2e^-;E^o_{(H_2/H^{+})}=0.0V$

Option d: $Ag$

This metal can easily get oxidized to $Ag^{+}$ ion and the standard oxidation potential for this is -0.80 V

$Ag\rightarrow Ag^{+}+e^-;E^o_{(Ag/Ag^{+})}=-0.80V$

Option e: $Mg^{2+}$

This ion cannot be further oxidized because +2 is the most stable oxidation state of magnesium.

By looking at the standard oxidation potential of the substances, the substance having highest positive $E^o$ potential will always get oxidized and will undergo oxidation reaction. Thus, considered as strong reducing agent.

From the above values, the correct answer is Option b.

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3 years ago