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1 year ago

PLEASEEEE HELP MEEEEE

Chemistry

2 answers:

fiasKO [112]1 year ago

6 0

Answer:

3.82 x 10²¹ molecules As₂O₃

Explanation:

To find the amount of molecules arsenic (III) oxide (As₂O₃), you need to (1) convert kg to lbs, then (2) convert g As₂O₃ to moles As₂O₃ (via molar mass), and then (3) convert moles to molecules (via Avogadro's number).

1 kilogram = 2.2 lb

Molar Mass (As₂O₃): 2(74.992 g/mol) + 3(15.998 g/mol)

Molar Mass (As₂O₃): 197.978 g/mol

Avogadro's Number:

6.022 x 10²³ molecules = 1 mole

0.0146 g As₂O₃ 1 kg 189 lb
------------------------ x --------------- x ------------------ x ................
1 kg 2.2 lb

1 mole 6.022 x 10²³ molecules
x ------------------ x --------------------------------------- = 3.82 x 10²¹ molecules As₂O₃
197.978 g 1 mole

Arturiano [62]1 year ago

4 0

3.82 x10^21 molecules As2O3

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A typical aspirin tablet contains 327 mg of acetylsalicylic acid, HC9H7O4. Calculate the pH of a solution that is prepared by di

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2 years ago

What volume of nitrogen dioxide is formed at 735 torr and 28.2 °C by reacting 3.56 cm3 of copper (d = 8.95 g/cm3) with 200 mL of

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So, Mass= Density * Volume = 8.95 g/cm³ * 3.56 cm³ = 31.862 g

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The formula for the calculation of moles is shown below:

$moles = \frac{Mass\ taken}{Molar\ mass}$

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$Moles= \frac{31.862\ g}{63.546\ g/mol}$

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Given, Volume of nitric acid solution = 200 mL = 200 cm³

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Considering the expression for density as:

$Density=\frac {Mass}{Volume}$

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So, Mass= Density * Volume = 1.42 g/cm³ * 200 cm³ = 284 g

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The formula for the calculation of moles is shown below:

$moles = \frac{Mass\ taken}{Molar\ mass}$

Thus,

$Moles= \frac{193.12\ g}{63.01\ g/mol}$

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0.5014 moles of copper react with 4*0.5014 moles of nitric acid

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The formation of the product is governed by the limiting reagent. So,

1 mole of copper on reaction forms 2 moles of nitrogen dioxide

So,

0.5014 mole of copper on reaction forms 2*0.5014 moles of nitrogen dioxide

Moles of nitrogen dioxide = 1.0028 moles

Given:

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The conversion of P(torr) to P(atm) is shown below:

$P(torr)=\frac {1}{760}\times P(atm)$

So,

Pressure = 735 / 760 atm = 0.9632 atm

Temperature = 28.2 °C

The conversion of T( °C) to T(K) is shown below:

T(K) = T( °C) + 273.15

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T₁ = (28.2 + 273.15) K = 301.35 K

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PV=nRT

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P is the pressure

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T is the temperature

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Applying the equation as:

0.9632 atm × V = 1.0028 mol × 0.0821 L.atm/K.mol × 301.35 K

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