What is the only true way to tell if a chemical reaction has occurred? CFU

The emission spectrum of hydrogen shows discrete, bright, colored lines. Which characteristic of the Bohr model is best supporte

maw [93]

Answer is: d.Electrons cannot exist in locations other than in specific orbits.

According to the Bohr model of the atom:

1. Energy levels of electrons are discrete (certain discrete values of energy)., that is why hydrogen shows discrete, bright, colored lines.

2. Electrons orbit the nucleus in orbits that have a set size and energy.

3. Electrons can jump from one energy level to another, absorbing or emitting electromagnetic radiation with a frequency ν (energy difference of the levels).

5 0

3 years ago

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Iron(III) oxide and hydrogen react to form iron and water, like this: (s)(g)(s)(g) At a certain temperature, a chemist finds tha

stepan [7]

The question is incomplete, here is the complete question:

Iron(III) oxide and hydrogen react to form iron and water, like this:

$Fe_2O_3(s)+3H_2(g)\rightarrow 2Fe(s)+3H_2O(g)$

At a certain temperature, a chemist finds that a 5.4 L reaction vessel containing a mixture of iron(III) oxide, hydrogen, iron, and water at equilibrium has the following composition:

Compound Amount

$Fe_2O_3$ 3.54 g

$H_2$ 3.63 g

Fe 2.37 g

$H_2O$ 2.13 g

Calculate the value of the equilibrium constant for this reaction. Round your answer to 2 significant digits

Answer: The value of equilibrium constant for the given reaction is $2.8\times 10^{-4}$

Explanation:

To calculate the molarity of solution, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Mass of solute}}{\text{Molar mass of solute}\times \text{Volume of solution (in L)}}$

For hydrogen gas:

Given mass of hydrogen gas = 3.63 g

Molar mass of hydrogen gas = 2 g/mol

Volume of solution = 5.4 L

Putting values in above equation, we get:

$\text{Molarity of hydrogen gas}=\frac{3.63}{2\times 5.4}\\\\\text{Molarity of hydrogen gas}=0.336M$

For water:

Given mass of water = 2.13 g

Molar mass of water = 18 g/mol

Volume of solution = 5.4 L

Putting values in above equation, we get:

$\text{Molarity of water}=\frac{2.13}{18\times 5.4}\\\\\text{Molarity of water}=0.0219M$

The given chemical equation follows:

$Fe_2O_3(s)+3H_2(g)\rightarrow 2Fe(s)+3H_2O(g)$

The expression of $K_c$ for above equation follows:

$K_c=\frac{[H_2O]^3}{[H_2]^3}$

The concentration of pure solids and pure liquids are taken as 1 in equilibrium constant expression. So, the concentration of iron and iron (III) oxide is not present in equilibrium constant expression.

Putting values in above equation, we get:

$K_c=\frac{(0.0219)^3}{(0.336)^3}\\\\K_c=2.77\times 10^{-4}$

Hence, the value of equilibrium constant for the given reaction is $2.8\times 10^{-4}$

7 0

3 years ago

Write the net ionic equation for the reaction of barium chloride and sodium sulfate.

lana [24]

The answer is Ba2+ + SO4 2- => BaSO4

7 0

3 years ago

What is the pH of a 0.28 M solution of ascorbic acid (Vitamin C)? (The values for Ka1 and Ka2 for ascorbic acid are 8.0×10−5 and

Tomtit [17]

Answer:

pH = 2.32

Explanation:

H2A + H2O -------> H3O+ + HA-

Ka2 is very less so i am not considering that dissociation.

now Ka = 8.0×10−5

= [H3O+] [HA-] / [H2A]

lets concentration of H3O+ = X then above equation will be

8.0×10−5 = [X] [X] / [0.28 -X]

8.0×10−5 = X2 / [0.28 -X]

X2 + 8.0×10−5 X - 2.24 x 10−5

solve the quardratic equation

X =0.004693 M

pH = -log[H+}

= -log [0.004693]

= 2.3285

≅2.32

pH = 2.32

5 0

3 years ago

Which is older? Dinosaurs or Grasshoppers?

Serjik [45]

Answer:

i think grass hopper

Explanation:

answer my question i am am brainiest

3 0

3 years ago

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