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3 years ago

What is the new solution concentration when 150. mL of water is added to 200. mL of a 3.55 M HBr solutions.

Chemistry

1 answer:

Agata [3.3K]3 years ago

3 0

Answer:

The new concentration is 2.03M

Explanation:

Step 1: Data given

A 200 mL 3.55 M HBr is diluted with 150 mL

Step 2: The dilution

In a dilution, the ratio that exists between the concentration of the stock solution and the concentration of the diluted solution equals the ratio that exists between the volume of the diluted solution and the volume of the stock solution.

Dilution factor = [stock sample]/[diluted sample] = diluted volume / stock volume

In this case, the volume of the stock solution is 200 mL

Adding 150 mL of water to the stock solution will dilute it to a final volume of 200 + 150 = 350 mL

The dilution factor wll be 350/200 = 1.75

This makes the diluted concentration:

3.55/1.75 = 2.03M

The new concentration is 2.03M

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Formula used :

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$\Delta (H_{f})_{reaction}=(2\times \Delta H_{Al_{2}O_{3}(s)}+3\times \Delta H_{Mn(s)} )-(3\times \Delta H_{MnO_{2}(s) }+4\times\Delta H_{Al}(s))$

We know that the standard enthalpy of formation of the element is equal to Zero.

Therefore, the enthalpy of formation of (Mn) and (Al) is equal to zero.

Now, put all the values in above formula, we get

$\Delta (H_{f})_{reaction}=[2moles\times (-1699.8 KJ/mole)}+3moles\times (0\text{ KJ/mole}})]-[(3moles\times(-520.0KJ/mole }+4moles\times(0\text{ KJ/mole})]$

= (-3399.6) + (1560)

= -1839.6 KJ

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