Tectonic plates make up which of the following layers of the Earth?

g Calculate the pH when (a) 24.9 mL and (b) 25.1 mL of 0.100 M HNO3 have been added to 25.0 mL of 0.100 M KOH solution.

jarptica [38.1K]

Answer:

Following are the responses to the given choices:

Explanation:

For point a:

Using the acid and base which are strong so,

moles of $H^+$ (from $HNO_3$ )

$= 24.9\ mL \times 0.100\ M \\\\= \frac{24.9}{1000\ L} \times 0.100\ M \\\\= 2.49 \times 10^{-3} \ mol$

moles of $OH^{-}$ (from $KOH$ )

$= 25.0\ mL \times 0.100\ M \\\\= \frac{25.0}{1000 \ L} \times 0.100 \ M \\\\\= 2.50 \times 10^{-3}\ mol$

$1\ mol H^{+} \ neutralizes\ 1\ mol\ of\ OH^{-}$

So, $(2.50 \times 10^{-3} mol - 2.49 \times 10^{-3} mol)$ i.e. $1 \times 10^{-5}$ mol of $OH^-$ in excess in total volume $(24.9+25.0) \ mL = 49.9 \ mL$ i.e. concentration of $OH^- = 2 \times 10^{-4}\ M$

$p[OH^{-}] = -\log [OH^{-}] = -\log [2 \times 10^{-4}\ mol] = 3.70$

Since, $pH + pOH = 14,$

so,

$\to pH = 14- pOH = 14- 3.70 = 10.30$

For point b:

moles of $OH^-$ = from point a $= 2.50 \times 10^{-3} \ mol$

moles of $H^+$ (from $HNO_3$ ):

$= 25.1 mL \times 0.100 M\\\\ = \frac{25.1}{1000}\ L \times 0.100 \ M\\\\ = 2.51\times 10^{-3} \ mol$

1 mol $H^+$ neutralizes 1 mol of $OH^-$

So, $(2.51 \times 10^{-3}\ mol - 2.50 \times 10^{-3}\ mol)$ i.e. $1 \times 10^{-5} \ mol \ of\ H^+$ in excess in the total volume of $(25.1+25.0) \ mL = 50.1\ mL$ i.e. concentration of $H^+ = 2 \times 10^{-4}\ M$

Hence, $pH = -\log [H^+] = -\log[2 \times 10^{-4}] = 3.70$

6 0

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The law of conservation of energy describes the total amount of energy in a system. Which statements explain why the conservatio

Advocard [28]

It is a statement of fact. explains how energy is produced, and describes the behavior of energy.

3 0

4 years ago

Two well-known complex ions containing ni are [ni(h2o)6]2+, which is green, and [ni(en)3]2+, which is purple. which one of these

Julli [10]

For [Ni(en)³]²⁺ which is purple, the crystal field splitting energy is greater than the complex ion, [Ni(H₂O)₆]²⁺ which is green in color.
When a Lewis base id attached to the metal ion by covalent bond, then the complex ion is formed and when these complex ions are present with other ions of opposite charge or neutral charge, they will make complex compounds.

7 0

3 years ago

A particular forest is 10,000 acres. Determine its size in hectares. (1 hectare = 2.47

igor_vitrenko [27]

Taking into account the change of units, a particular forest is 4,048.58 hectares.

<h3>Definition of rule of three</h3>

The rule of three is a way of solving problems of proportionality between three known values and an unknown value, establishing a relationship of proportionality between all of them.

If the relationship between the magnitudes is direct, the direct rule of three must be applied using the following formula, where a, b and c known data and x the variable to be calculated:

a ⇒ b

c ⇒ x

So: x= (c×b)÷ a

The direct rule of three is the rule applied in this case where there is a change of units.

<h3>Size in hectareas</h3>

To perform in this case the conversion of units, you must first know that 1 hectare = 2.47 acres.

So, the rule of three can be used as follow: if 2.47 acres is 1 hectare, 10,000 acres equals how many hectares?

2.47 acres ⇒ 1 hectare

10,000 acres ⇒ x

So: x= (10,000 acres ×1 hectare)÷ 2.47 acres

Solving:

<u><em>x= 4,048.58 hetares</em></u>

In summary, a particular forest is 4,048.58 hectares.

Learn more with this example:

brainly.com/question/12482948

#SPJ1

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Answer:

discupaeu não sei

um belo dia abençoado

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