What is the purpose of the scientific method

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

RSB [31]

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

Explanation:

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

3 years ago

Consultați sistemul periodic și aranjați în ordinea creșterii caracterului nemetalic următoarele elemente:

lukranit [14]

I’m sorry I just really need points rn I love you

7 0

2 years ago

What substances make up water?

ziro4ka [17]

A water molecule consists of three atoms; an oxygen atom and two hydrogen atoms, which are bond together like little magnets.

An iron pot is made up of only one substance, iron. Iron is an element classified as a transition metal

Iron. Elementsare pure substances that are made up of one kind of atom. Pizza is not an element because it is a mixture of many substances. Water is a pure substance, but it contains two kindsof atom: oxygen and hydrogen.

8 0

3 years ago

Read 2 more answers

C(S)+O2(g)-->CO2(g)

soldi70 [24.7K]

Answer: The correct answer is 1.18 g.

Explanation:

We are given a chemical equation:

$C(S)+O2(g)\rightarrow CO_2(g)$