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padilas [110]
3 years ago
14

The reaction of hydrogen(g) with fluorine(g) to form hydrogen fluoride(g) proceeds as follows: H2(g) + F2(g) 2 HF(g) When 0.647

grams of H2(g) react with sufficient F2(g) , 174 kJ of energy are evolved . What is the value of H for the chemical equation given? ΔHrxn = kJ
Chemistry
1 answer:
Nata [24]3 years ago
6 0

<u>Answer:</u> The value of \Delta H for the reaction will be -537 kJ

<u>Explanation:</u>

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

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

Given mass of hydrogen gas = 0.647 g

Molar mass of hydrogen gas = 2 g/mol

Putting values in above equation, we get:

\text{Moles of hydrogen gas}=\frac{0.647g}{2g/mol}=0.324mol

We are given:

Energy released for 0.324 moles of hydrogen reacted is 174 kJ

For the given chemical reaction:

H_2(g)+F_2(g)\rightarrow 2HF(g)

By Stoichiometry of the reaction:

When 0.324 moles of hydrogen gas is reacted, the energy evolved is 174 kJ

So, when 1 mole of hydrogen gas will react, the energy evolved will be = \frac{174kJ}{0.324mol}\times 1mol=537kJ

<u>Sign convention of heat:</u>

When heat is absorbed, the sign of heat is taken to be positive and when heat is released, the sign of heat is taken to be negative.

Hence, the value of \Delta H for the reaction will be -537 kJ

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6 0
3 years ago
The density of mercury is 13.5g/mL. What is the volume of this liquid if the sample weighs 12.5 pounds?
Mama L [17]

Answer : The volume of liquid is 420 mL.

Explanation :

Density : The mass per unit volume of a substance is known as density.

Formula used:

\text{Density}=\frac{\text{Mass}}{\text{Volume}}

As we are given:

Density of mercury = 13.5 g/mL

Mass = 12.5 pounds

First we have to convert mass of sample from pound to gram.

Conversion used:

As, 1 pound = 453.6 g

So, 12.5 pounds = 453.6 × 12.5 g = 5670 g

Now we have to calculate the volume of liquid.

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Now putting all the given values in this formula, we get:

13.5g/mL=\frac{5670g}{\text{Volume}}

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7 0
3 years ago
What is the contrast of these two atoms?
Katena32 [7]

Answer:

The atomic number of silicon is 14 while atomic mass of carbon is 14.

Explanation:

An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.

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In given atoms ¹⁴₆C  and ²⁸₁₄Si the atomic mass of carbon is 14 while the atomic number of silicon is 14. It means silicon has 14 electrons or protons while carbon has 6 protons or electrons because its atomic number is 6. Carbon has 6 protons and 8 neutrons in its nucleus while silicon has 14 protons and 14 neutrons in its nucleus.

In C:

Number of neutrons + protons = 8 + 6 = 14 amu (mass number)

Number of electrons = 6

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6 0
3 years ago
The equilibrium constant for the reaction of carbon monoxide with water is 1.845. if 1.00 mol of each reactant is placed in a 2.
SpyIntel [72]
[CO] = 1 mol / 2L = 0.5 M

[
According to the equation:

and by using the ICE table:

             CO(g) + H2O(g) ↔   CO2(g) + H2(g)

initial     0.5            0.5                    0          0

change  -X              -X                   +X         +X
     
Equ       (0.5-X)       (0.5-X)                     X            X

when Kc = X^2 * (0.5-X)^2

by substitution:

1.845 = X^2 * (0.5-X)^2  by solving for X 

∴X = 0.26

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4 0
2 years ago
There are many compounds that contribute to the overall aroma of a banana. The primary compound is called isoamyl acetate and co
Murljashka [212]

Explanation:

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Moles of Oxygen = 32.28/16 = 2.018mol

Mole Ratio of C : H : O

= 5.048 : 7.07 : 2.018

= 5 : 7 : 2.

Hence the empirical formula of isoamyl acetate is C5H7O2.

8 0
2 years ago
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