How does nuclear reactor produce electricty

Instant cold packs, often used to ice athletic injuries on the field, contain ammonium nitrate and water separated by a thin pla

RSB [31]

<u>Answer:</u> The enthalpy change of the reaction is -27. kJ/mol

<u>Explanation:</u>

To calculate the mass of water, we use the equation:

$\text{Density of substance}=\frac{\text{Mass of substance}}{\text{Volume of substance}}$

Density of water = 1 g/mL

Volume of water = 25.0 mL

Putting values in above equation, we get:

$1g/mL=\frac{\text{Mass of water}}{25.0mL}\\\\\text{Mass of water}=(1g/mL\times 25.0mL)=25g$

To calculate the heat released by the reaction, we use the equation:

$q=mc\Delta T$

where,

q = heat released

m = Total mass = [1.25 + 25] = 26.25 g

c = heat capacity of water = 4.18 J/g°C

$\Delta T$ = change in temperature = $T_2-T_1=(21.9-25.8)^oC=-3.9^oC$

Putting values in above equation, we get:

$q=26.25g\tiimes 4.18J/g^oC\times (-3.9^oC)=-427.9J=-0.428kJ$

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass of ammonium nitrate = 1.25 g

Molar mass of ammonium nitrate = 80 g/mol

Putting values in above equation, we get:

$\text{Moles of ammonium nitrate}=\frac{1.25g}{80g/mol}=0.0156mol$

To calculate the enthalpy change of the reaction, we use the equation:

$\Delta H_{rxn}=\frac{q}{n}$

where,

q = amount of heat released = -0.428 kJ

n = number of moles = 0.0156 moles

$\Delta H_{rxn}$ = enthalpy change of the reaction

Putting values in above equation, we get:

$\Delta H_{rxn}=\frac{-0.428kJ}{0.0156mol}=-27.44kJ/mol$

Hence, the enthalpy change of the reaction is -27. kJ/mol

4 0

4 years ago

Arrhenius base definition

kompoz [17]

Arrhenius base is a substance that , when dissolved in an aqueous solution , increase the concentration of hydroxide (OH) ion in the solution

I hope that's help !

6 0

3 years ago

Mary starts from her house, walks 80 meters south, and stops to chat with her aunt on the sidewalk. After chatting for a few min

Olenka [21]

(80+125+45) / 10 = 250/10 =25
25 meters per minute= 0.41 meters/second

the direction and stopping time is irrelevant to the problem.

6 0

4 years ago

Merits of modern periodic table?

ANEK [815]

Answer:

<h3>Merits of modern periodic table:</h3>

The wrong position of some elements like argon, potassium, cobalt and nickel due to atomic weights have been solved by arranging the elements in the order of increasing atomic number without changing their own places.
The isotopes of some element have the same atomic numbers. Therefore, they find the same position in periodic table.
It separates metals from non-metals.
The groups of the table are divided into sub groups A and B due to their dissimilar properties which make the study of elements specific and easier.
The representative and transition elements have been separated.

Hope this helps...

Good luck on your assignment...

6 0

3 years ago

What is the solubility of a solid in a solvent?

patriot [66]

Answer:

Solubility is a chemical property referring to the ability for a given substance, the solute, to dissolve in a solvent. It is measured in terms of the maximum amount of solute dissolved in a solvent at equilibrium. ... The solvent is often a solid, which can be a pure substance or a mixture.

Explanation:

5 0

3 years ago