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2 years ago

I need help with this! I don't fully understand it

Chemistry

1 answer:

ZanzabumX [31]2 years ago

6 0

Answer:

1. highest is 25.7c° and lowest is 20.0c°

2.Is Exothermic. An Endothermic Reaction is a chemical reaction that absorbs energy in the form of light or heat. In it, the energy or enthalpy of the reactants is less than that of the products. An Exothermic Reaction is a chemical reaction that gives off energy in the form of light or heat.

3. Reactans.

4. The substance(s) to the left of the arrow in a chemical equation are called reactants. A reactant is a substance that is present at the start of a chemical reaction. The substance(s) to the right of the arrow are called products . A product is a substance that is present at the end of a chemical reaction.

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A sample of water is heated from 60.0 °C to 75.0°C by the addition of 140 j of

kupik [55]

Mass of the water : 2.23 g

<h3>Furter explanation</h3>

Heat

Q = m.c.Δt

m= mass, g

c = heat capacity, for water : 4.18 J/g° C.

ΔT = temperature

Q= 140 J

Δt = 75 - 60 = 15

mass of the water :

$\tt m=\dfrac{Q}{c.\Delta T}=\dfrac{140}{4.18\times 15}=2.23~g$

5 0

3 years ago

How many moles are present in 4.7 liters of argon gas as STP

algol [13]

Answer:

0.21mol Ar (g)

Explanation:

To convert from litres to moles at STP we must divide the amount of litres by 22.4.

4.7 / 22.4 = 0.21mol Ar (g)

5 0

3 years ago

Read 2 more answers

Ms.markas takes a thermos bottle filled with hot coffee to work each day. The thermos bottle keeps the coffe hot by

Juliette [100K]

D is the answer. The thermo works as an insulator minimizing the heat loss to the environment.

5 0

3 years ago

Use the following half-reactions to construct a voltaic cell:

velikii [3]

<u>Answer:</u> The correct answer is $3Ag^+(aq.)+Cr(s)\rightarrow 3Ag(s)+Cr^{3+}(aq.);E^o_{cell}=+1.53V$

<u>Explanation:</u>

We are given:

$Cr^{3+}(aq.)+3e^-\rightarrow Cr(s);E^o=-0.73V\\\\Ag^+(aq.)+e^-\rightarrow Ag(s);E^o=+0.80V$

The substance having highest positive $E^o$ potential will always get reduced and will undergo reduction reaction. Here, silver will always undergo reduction reaction will get reduced.

Chromium will undergo oxidation reaction and will get oxidized.

The half reactions for the above cell is:

Oxidation half reaction: $Cr(s)\rightarrow Cr^{3+}+3e^-;E^o_{Cr^{3+}/Cr}=-0.73V$

Reduction half reaction: $Ag^{+}+e^-\rightarrow Ag(s);E^o_{Ag^{+}/Ag}=0.80V$ ( × 3)

Net equation: $3Ag^+(aq.)+Cr(s)\rightarrow 3Ag(s)+Cr^{3+}(aq.)$

Oxidation reaction occurs at anode and reduction reaction occurs at cathode.

To calculate the $E^o_{cell}$ of the reaction, we use the equation:

$E^o_{cell}=E^o_{cathode}-E^o_{anode}$

Putting values in above equation, we get:

$E^o_{cell}=0.80-(-0.73)=1.53V$

Hence, the correct answer is $3Ag^+(aq.)+Cr(s)\rightarrow 3Ag(s)+Cr^{3+}(aq.);E^o_{cell}=+1.53V$

4 0

3 years ago

An important step in science is supporting a theory or idea without data. The questions we ask determine the type of data we col

san4es73 [151]

Answer:

What will happen to Uk if you double the mass?

Explanation:

Uk = 0.5 * m * v²

You see that both m and v are variable, which means that both m and v can be any number. Regardless of the numbers you put in for m or v, the formula to calculate the kinetic energy (Uk) remains valid.

You could ask

1. What will happen to Uk if you double the mass?

2. What will happen to Uk if you double the velocity?

please see and understand(!) that the relationship between Uk an v² is indeed the velocity squared....

EXTRA

Uk = 0.5 * m * (v)²

Suppose the m = 3kg and velocity = 5 m/s

What is the Uk?

Well if you know the formula you can use your calculator to find out:

Uk = 0.5 * m * (v)²

Uk = 0.5 * 3 * (5)²

Uk = 0.5 * 3 * 25

Uk = 37.5 kgm/s²

Again you ask what will happen to Uk if you double the velocity?

At first it was 5 m/s and now it doubles, which means it now has that value *2

The new velocity is 5 *2 = 10 m/s

Uk = 0.5 * m * (v)²

Uk = 0.5 * 3 * (10)²

Uk = 0.5 * 3 * 100

Uk = 150 kgm/s²

150 = 4 * 37.5

So now you see that if you double your velocity, the Uk will be 2² = 4 times as big !

3 0

3 years ago