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3 years ago

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The solid block shown below has a mass of 146 grams. THE DIMENSIONS OF THE BLOCK ARE- 3.0 cm by 4.5 cm by 7.0 cm. What is the bl

ock’s density? D=m/v

1 answer:

Amiraneli [1.4K]3 years ago

5 0

Explanation:

D=m÷v

D=146÷(3×4.5×7)

D=146÷94.5

D=1.54g/cm^3

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Answer:

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The NH₃ reacts with HCl producing NH₄⁺, thus:

NH₃ + HCl → NH₄⁺ + Cl⁻

<em>That means, moles of HCl added to the solution are the same moles are consumed of NH₃ and produced of NH₄⁺</em>

Moles added of HCl were:

0.025L ₓ (0.20mol / L) = 0.0050 moles of HCl. Thus, final moles of NH₃ and NH₄⁺ are:

NH₃: 0.0200 moles - 0.0050 moles = 0.0150 moles

NH₄⁺: 0.0200 moles + 0.0050 moles = 0.0250 moles.

Using H-H equation for bases:

pOH = pKb + log [NH₄⁺] / [NH₃]

<em>Where pKb is -log Kb =</em><em> 4.745</em><em>.</em>

Replacing:

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pOH = 4.967

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