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2 years ago

How much heat is released when 15.7g of methane (c2h6) is combusted if the enthalpy of the reaction is - 1560.7 kj

Chemistry

1 answer:

lyudmila [28]2 years ago

5 0

- 407.4 kJ of heat is released.

<u>Explanation:</u>

We have to write the balanced equation as,

2 C₂H₆(g) + 7O₂ → 4CO₂ + 6H₂O

Here 2 moles of ethane reacts in this reaction.

Now we have to find out the amount of ethane reacted using its given mass and molar mass as,

2 mol C₂H₆ × 30.07 g of C₂H₆ / 1 mol C₂H₆ = 60.14 g of C₂H₆

Heat released = ΔH × given mass / 60.14

= - 1560. 7 kj ×15.7 g / 60. 14 g = -407. 4 kJ

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Given the following heats of combustion. CH3OH(l) + 3/2 O2(g) CO2(g) + 2 H2O(l) ΔH°rxn = -726.4 kJ C(graphite) + O2(g) CO2(g) ΔH

sergeinik [125]

Answer:

The standard enthalpy of formation of methanol is, -238.7 kJ/mole

Explanation:

The formation reaction of CH_3OH will be,

$C(s)+2H_2(g)+\frac{1}{2}O_2\rightarrow CH_3OH(g),\Delta H_{formation}=?$

The intermediate balanced chemical reaction will be,

$C(graphite)+O_2(g)\rightarrow CO_2(g), \Delta H_1=-393.5kJ/mole$ ..[1]

$H_2(g)+\frac{1}{2}O_2(g)\rightarrow H_2O(l), \Delta H_2=-285.8kJ/mole$ ..[2]

$CH_3OH(g)+\frac{3}{2}O_2(g)\rightarrow CO_2(g)+2H_2O(l) , \Delta H_3=-726.4kJ/mole$ ..[3]

Now we will reverse the reaction 3, multiply reaction 2 by 2 then adding all the equations, Using Hess's law:

We get :

$C(graphite)+O_2(g)\rightarrow CO_2(g) , \Delta H_1=-393.5kJ/mole$ ..[1]

$2H_2(g)+2O_2(g)\rightarrow 2H_2O(l) ,\Delta H_2=2\times (-285.8kJ/mole)=-571.6kJ/mol$ ..[2]

$CO_2(g)+2H_2O(l)\rightarrow CH_3OH(g)+\frac{3}{2}O_2(g) ,\Delta H_3=726.4kJ/mole$ [3]

The expression for enthalpy of formation of $C_2H_4$ will be,

$\Delta H_{formation}=\Delta H_1+2\times \Delta H_2+\Delta H_3$

$\Delta H=(-393.5kJ/mole)+(-571.6kJ/mole)+(726.4kJ/mole)$

$\Delta H=-238.7kJ/mole$

The standard enthalpy of formation of methanol is, -238.7 kJ/mole

4 0

2 years ago

Which of the following describes the properties of a substance?

Anestetic [448]

The answer is A how it react with other chemicals

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6 0

2 years ago

Read 2 more answers

How many atoms are in 169g of calcium?

uysha [10]

The answer is 6.022• 10^23 atoms

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3 years ago

A 1.00 liter solution contains 0.24 M hypochlorous acid and 0.31 M sodium hypochlorite. If 0.160 moles of potassium hydroxide ar

ryzh [129]

Explanation:

When OH- (as in potassium hydroxide) is added, it reacts with the acid (HOCl) to reduce the amount of HOCl and increase the concentration of sodium hypochlorite.

Potassium hydroxide will react with the hypochlorous acid to produce hypochlorite ions. In the process, some of the weak acid will be consumed, along with the added strong base.

This occurs as follows:

HClO(aq) + KOH(aq) → KClO(aq) + H2O(l)

since water is formed, this maintains the pH. Thus ...

A. The number of moles of HClO will decrease. - TRUE

B. The number of moles of ClO- will increase. - TRUE

C. The equilibrium concentration of H3O+ will remain the same. - TRUE

D. The pH will decrease. - FALSE

E. The ratio of [HClO] / [ClO-] will decrease. -TRUE. It will decrease as HClO goes down and ClO- goes up.

5 0

3 years ago

Immunoglobulin G (IgG), formerly called gamma globulin, is a principal antibody in blood serum. A 0.470 g sample of immunoglobul

Nookie1986 [14]

The molecular mass of the immunoglobulin G, given the data from the question is 1.53×10⁵ g/mole

<h3>How to determine the molarity</h3>

We'll begin by calculating the molarity of the immunoglobulin G. This is illustrated below:

Volume = 0.106 L
Temperature (T) = 25 °C = 25 + 273 = 298 K
Osmotic pressure (π) = 0.733 mbar = 0.733 × 0.000987 = 0.00072 atm
Gas constant (R) = 0.0821 atm.L/Kmol
Van't Hoff factor (i) = 1
Molarity (M)

π = iMRT

M = π / iRT

M = 0.00072 / (1 × 0.0821 × 298)

M = 0.000029 M

<h3>How to determine the mole of immunoglobulin G</h3>

Molarity = 0.000029 M
Volume = 0.106 L
Mole =?

Mole = Molarity × volume

Mole = 0.000029 × 0.106

Mole = 3.074×10⁻⁶ mole

<h3>How to determine the molar mass of mmunoglobulin G</h3>

Mole = 3.074×10⁻⁶ mole
Mass = 0.470 g
Molar mass =?

Molar mass = mass / mole

Molar mass = 0.47 / 3.074×10⁻⁶

Molar mass = 1.53×10⁵ g/mole

Learn more about Osmotic pressure:

brainly.com/question/5925156

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5 0

2 years ago