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3 years ago

The phase change h2(g) → h2(s) is called , and the enthalpy change, δh, for this phase change has a sign.

1 answer:

7 0

The phase change H₂(g) → H₂(s) is called deposition, and the enthalpy change, ΔH, for this phase change has a negative (-) sign.
Deposition is a thermodynamic process in which gas transforms into solid without passing through the liquid phase. Example is formin snow in clouds directly from water vapor. In deposition energy is released.

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Which of the following shows a decrease in entropy?

shusha [124]

Precipitation hope this helped you

4 0

3 years ago

Which would have more mass: a mole of sodium or a mole of copper? How do you know?

bearhunter [10]

Answer:

copper

Explanation:

so for this you can work out the mass for both and compare

so mass = moles × mr

so mass of sodium = 1 × 23= 23 g

and mass of copper = 1 × 63.5= 63.5 g

so copper have more mass :)

5 0

2 years ago

Which is not a compound? water silicon dioxide oxygen gas carbon dioxide gas

Illusion [34]

All of these are compounds except oxygen because a compound is two or more different elements bonded together.

4 0

3 years ago

Please help :)

eimsori [14]

Distance and period of time

6 0

3 years ago

The dissociation of sulfurous acid (H2SO3) in aqueous solution occurs as follows:

aksik [14]

Answer:

The [SO₃²⁻]

Explanation:

From the first dissociation of sulfurous acid we have:

H₂SO₃(aq) ⇄ H⁺(aq) + HSO₃⁻(aq)

At equilibrium: 0.50M - x x x

The equilibrium constant (Ka₁) is:

$K_{a1} = \frac{[H^{+}] [HSO_{3}^{-}]}{[H_{2}SO_{3}]} = \frac{x\cdot x}{0.5 - x} = \frac {x^{2}}{0.5 -x}$

With Ka₁= 1.5x10⁻² and solving the quadratic equation, we get the following HSO₃⁻ and H⁺ concentrations:

$[HSO_{3}^{-}] = [H^{+}] = 7.94 \cdot 10^{-2}M$

Similarly, from the second dissociation of sulfurous acid we have:

HSO₃⁻(aq) ⇄ H⁺(aq) + SO₃²⁻(aq)

At equilibrium: 7.94x10⁻²M - x x x

The equilibrium constant (Ka₂) is:

$K_{a2} = \frac{[H^{+}] [SO_{3}^{2-}]}{[HSO_{3}^{-}]} = \frac{x^{2}}{7.94 \cdot 10^{-2} - x}$

Using Ka₂= 6.3x10⁻⁸ and solving the quadratic equation, we get the following SO₃⁻ and H⁺ concentrations:

$[SO_{3}^{2-}] = [H^{+}] = 7.07 \cdot 10^{-5}M$

Therefore, the final concentrations are:

[H₂SO₃] = 0.5M - 7.94x10⁻²M = 0.42M

[HSO₃⁻] = 7.94x10⁻²M - 7.07x10⁻⁵M = 7.93x10⁻²M

[SO₃²⁻] = 7.07x10⁻⁵M

[H⁺] = 7.94x10⁻²M + 7.07x10⁻⁵M = 7.95x10⁻²M

So, the lowest concentration at equilibrium is [SO₃²⁻] = 7.07x10⁻⁵M.

I hope it helps you!

8 0

3 years ago

The phase change h2(g) → h2(s) is called ________, and the enthalpy change, δh, for this phase change has a ________ sign.

The phase change h2(g) → h2(s) is called , and the enthalpy change, δh, for this phase change has a sign.