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3 years ago

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Chemistry

1 answer:

natali 33 [55]3 years ago

8 0

Answer:

I would say is B but I do t really know

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what is the pH of a solution that results when 0.010mol HNO3 is added to 500.ml of a solution that is 0.10M in aqueous ammonia a

WARRIOR [948]

Answer : The

pH of a solution is, 8.56

Explanation : Given,

$K_b=1.8\times 10^{-5}$

Concentration of ammonia (base) = 0.10 M

Concentration of ammonium nitrate (salt) = 0.55 M

First we have to calculate the value of $pK_b$ .

The expression used for the calculation of $pK_b$ is,

$pK_b=-\log (K_b)$

Now put the value of $K_b$ in this expression, we get:

$pK_b=-\log (1.8\times 10^{-5})$

$pK_b=5-\log (1.8)$

$pK_b=4.7$

Now we have to calculate the pOH of buffer.

Using Henderson Hesselbach equation :

$pOH=pK_b+\log \frac{[Salt]}{[Base]}$

Now put all the given values in this expression, we get:

$pOH=4.7+\log (\frac{0.55}{0.10})$

$pOH=5.44$

The pOH of buffer is 5.44

Now we have to calculate the pH of a solution.

$pH+pOH=14\\\\pH+5.44=14\\\\pH=14-5.44\\\\pH=8.56$

Thus, the pH of a solution is, 8.56

8 0

3 years ago

In the following balanced neutralization reaction equation, how many moles of Ca(OH)2 are required to completely neutralize 1.2

Delvig [45]

<span>2HI + Ca(OH)2 --> Cal + 2H2O. According to stoichiometry, 2 moles of HI reacts with 1 mole of Ca(OH)2. Therefore, 1.2 moles of HI will react with = 1.2/2 = 0.6 moles of Ca(OH)2. Hope this helps.</span>

7 0

3 years ago

In state n = 1, the energy of the hydrogen atom is -13.58 ev. what is its energy in state n = 2?

Gekata [30.6K]

The energy of a hydrogen atom in energy level n = 2 is 3.4 eV.

The ionization of energy of the hydrogen atom is 13.6 eV.

This is the minimum energy required to raise the electron from its ground state in the hydrogen atom.

n represents the Energy level.

When an electron changes from one energy level to another, the energy of the atom must change as well. It requires energy to promote an electron from a lower energy level to a higher one. This energy can be supplied by a photon whose energy E is given in terms of its frequency E = hf or wavelength E = hc/λ.

The formula for the energy of an atom is:

E = 13.6 * $Z^{2}$ / $n^{2}$ .... this represents the allowed energy level in the hydrogen atom