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3 years ago

Calculate the molarity of a NaOH solution that is prepared by diluting 100mL of 0.20M NaOH with 150mL of H2O.

Chemistry

1 answer:

lianna [129]3 years ago

3 0

Molarity of solution = 0.08 M

<h3>Further explanation </h3>

Molarity shows the number of moles of solute in every 1 liter of solution or mmol in each ml of solution

$\tt M=\dfrac{n}{V}$

Where

M = Molarity

n = number of moles of solute

V = Volume of solution

mol of NaOH

$\tt mol=0.2~M\times 100~ml=20~mlmol=0.02~mol$

molarity

Volume of solution = 100 ml + 150 ml = 250 ml

$\tt M=\dfrac{0.02~mol}{0.250~L}=0.08$

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Explanation:

The given data is as follows.

m = 10.0 kg = 10,000 g (as 1 kg = 1000 g)

Initial temp. of block 1, $T_{1} = 100^{o}C$ = (100 + 273) K = 373 K

Initial temp. of block 2, $T_{2} = 0^{o}C$ = (0 + 273) K = 273 K

So, heat released by block 1 = heat gained by block 2

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$2T_{f} = 100^{o}C$

$T_{f} = 50^{o}C$

Convert temperature into kelvin as (50 + 273) K = 323 K.

Also, we know that the relation between enthalpy and temperature change is as follows.

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or, = 1243.5 kJ

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Now, entropy change for block 2 is as follows.

$\Delta S_{2} = mC ln \frac{T_{f}}{T_{i}}$

= $10000 g \times 0.385 J/K g \times ln \frac{323}{273}$

= $10000 g \times 0.385 J/K g \times 0.168$

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3 years ago

What is the density of a copper blocks if it has a mass of 43.5 grams and a volume of 4.85 cm^3?

Marianna [84]

8.97 g/cm^

D=m/v
D=43.5/4.85cm^3
D=8.97 g/cm^3

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