The process or method , by which a magnet loses its power , is called…………………… ..

90 POINTSSSS!!!

Katarina [22]

Answer:

$\large \boxed{\text{-2043.96 kJ/mol}}$

Explanation:

Assume the reaction is the combustion of propane.

Word equation: propane plus oxygen produces carbon dioxide and water

Chemical eqn: C₃H₈(g) + O₂(g) ⟶ CO₂(g) + H₂O(g)

Balanced eqn: C₃H₈(g) + 5O₂(g) ⟶ 3CO₂(g) + 4H₂O(g)

(a) Table of enthalpies of formation of reactants and products

$\begin{array}{cc}\textbf{Substance} & \textbf{$\Delta_{\text{f}}$H/(kJ/mol}) \\\text{C$_{3}$H$_{8}$(g)} & -103.85 \\\text{O}_{2}\text{(g)} & 0 \\\text{CO}_{2}\text{(g)} & -393.51 \\\text{H$_{2}$O(g)} & -241.82\\\end{array}$

(b)Total enthalpies of reactants and products

$\Delta_{\text{rxn}}H^{\circ} = \sum \left( \Delta_{\text{f}} H^{\circ} \text{products}\right) - \sum \left (\Delta_{\text{f}}H^{\circ} \text{reactants} \right)\\= \text{-2147.81 kJ/mol - (-103.85 kJ/mol)}\\= \text{-2147.81 kJ/mol + 103.85 kJ/mol}\\= \textbf{-2043.96 kJ/mol}\\\text{The enthalpy change is $\large \boxed{\textbf{-2043.96 kJ/mol}}$}$

ΔᵣH° is negative, so the reaction is exothermic.

5 0

2 years ago

Which element is smaller is atomic size?

Ganezh [65]

Answer:

Scandium is the smallest element of the four

Explanation:

Vanadium = 50.9415 u

Titanium = 47.867 u

Scandium = 44.955912 u

Chromium = 51.9961 u

3 0

2 years ago

A hardware salesman measures the mass of a box containing

sattari [20]

Step $1$

find the mass of a single washer

Divide the total mass by the number of washers

$\frac{0.4168}{1000} =0.0004168\ Kg$

$0.0004168kg=4.168*10^{-4} kg$

Step $2$

Convert kg to mg

we know that

$1 kg=1*10^{6} mg$

so

$4.168*10^{-4}*10^{6} =4.168*10^{2}mg=416.8 mg$

therefore

the answer is

$416.8 mg$

8 0

3 years ago

Read 2 more answers

Diatomic O2 can react with the element magnesium to form magnesium oxide (MgO). The balanced chemical equation is: 2Mg + O2 → 2M

tigry1 [53]

Answer:

We will expect 4 moles of MgO to be formed (option b).

Explanation:

Step 1: The balanced equation

2Mg + O2 → 2MgO

Step 2: Data given

Number of moles of Magnesium = 4 moles

Oxygen = in excess → this means Magnesium is the limiting reactant

Magnesium will completely be consumed ( 4 moles). There will remain 0 moles.

For 2 moles of magnesium consumed, we need 1 mole of oxygen to produce 2 moles of MgO.

For 4 moles of magnesium, we need 4/2 = 2 moles of oxygen.

For 4 moles of magnesium, we will produce 4/1 = 4 moles of MgO

We will expect 4 moles of MgO to be formed (option b).

4 0

2 years ago

Neptunium-237 was the first isotope of a transuranium element to be discovered. the decay constant is /s. what is the half-life

kari74 [83]

The half-life in years of Neptunium-237 which was the first isotope is 2.1 $10^{6}$ years.

Neptunium is most stable and Neptunium-237 is undergoes alpha decay, it means Neptunium-237 is decays by the emission of alpha particles . Seven alpha particles is emitted during decay of Neptunium-237. Neptunium-237 is radioactive actinide elements and first transuranium element.

The transuranium synthesis process involves creating a transuranium element through the transmutation process . The transmutation process is the process of creating heavy elements from light elements. Hence the process is the transmutation of light elements. There are two types: artificial and natural transmutation.

to learn more about transuranium element.

brainly.com/question/1491386

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6 0

1 year ago