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3 years ago

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Neon has a molar heat of vaporization of 1.80 kJ/mol at 24 K. How much heat must be absorbed to vaporize 5.97 mol of neon. A) 0.

302 kJ B) 3.32 kJ C) 10.7 kJ D) 258 kJ

1 answer:

Afina-wow [57]3 years ago

5 0

Answer:

A

Explanation:

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Through the complete electrolysis of a sample of pure water, a student collects 14.0 grams of hydrogen gas and 112.0 grams of ox

Vadim26 [7]

Answer:

126.0g of water were initially present

Explanation:

The electrolysis of water occurs as follows:

2H₂O(l) ⇄ 2H₂(g) + O₂(g)

<em>Where 2 moles of water produce 2 moles of hydrogen and 1 mole of oxygen.</em>

<em />

To find the mass of water we need to determine moles of oxygen and hydrogen, thus:

<em>Moles Hydrogen:</em>

14.0g H₂ ₓ (1mol / 2g H₂) = 7 moles H₂

<em>Moles Oxygen:</em>

112.0g O₂ ₓ (1mol / 32g) = 3.5 moles O₂

Based on the chemical equation, the moles of water initially present were 7 moles (That produce 7 moles H₂ and 3.5 moles O₂). The mass of 7 moles of H₂O is:

7 moles H₂O * (18g / mol) =

<h3>126.0g of water were initially present</h3>

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3 years ago

3.5g of a Certain compound X, known to be made of carbon, hydrogen, and perhaps oxygen, and to have a molecular molar mass of 15

shutvik [7]

Answer:

C₅H₁₀O₅

Explanation:

1. Calculate the mass of each element in 2.78 mg of X.

(a) Mass of C

$\text{Mass of C} = \text{5.13 g CO}_{2}\times \dfrac{\text{12.01 g C}}{\text{44.01 g }\text{CO}_{2}}= \text{1.400 g C}$

(b) Mass of H

$\text{Mass of H} = \text{2.10 g H$_{2}$O}\times \dfrac{\text{2.016 g H}}{\text{18.02 g H$_{2}$O}} = \text{0.2349 g H}$

(c) Mass of O

Mass of O = 3.5 - 1.400 - 0.2349 = 1.87 g

2. Calculate the moles of each element

$\text{Moles of C = 1400 mg C}\times\dfrac{\text{1 mmol C}}{\text{12.01 mg C }} = \text{116.6 mmol C}\\\\\text{Moles of H = 234.9 mg H} \times \dfrac{\text{1 mmol H}}{\text{1.008 mg H}} = \text{233.1 mmol H}\\\\\text{Moles of O = 1870 mg O} \times \dfrac{\text{1 mmol O}}{\text{16.00 mg O}} = \text{116 mmol O}$

3. Calculate the molar ratios

Divide all moles by the smallest number of moles.

$\text{C: } \dfrac{116.6}{116.6}= 1\\\\\text{H: } \dfrac{233.1}{116.6} = 1.999\\\\\text{O: } \dfrac{116}{116.6} = 1.00$

4. Round the ratios to the nearest integer

C:H:O = 1:2:1

5. Write the empirical formula

The empirical formula is CH₂O.

6. Calculate the molecular formula.

EF Mass = (12.01 + 2.016 + 16.00) u = 30.03 u

The molecular formula is an integral multiple of the empirical formula.

MF = (EF)ₙ

$n = \dfrac{\text{MF Mass}}{\text{EF Mass }} = \dfrac{\text{150 u}}{\text{30.03 u}} = 5.00 \approx 5$

MF = (CH₂O)₅ = C₅H₁₀O₅

The molecular formula of X is C₅H₁₀O₅.

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Iron is extracted from its ore (hematite) in the blast furnace. Which gas is produced as a waste product?

Diano4ka-milaya [45]

Answer:

CO2

Explanation:

CO2 or carbon dioxide is produced when iron is extracted from its ore. Carbon monoxide Co is used as reducing agent in iron extraction. In this reaction iron ore is reduced to iron and CO is oxidized to CO2 or carbon dioxide which is released in the process. There extraction of iron is redox reaction.

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I think it would be:
Is the author stating fact or opinion?
Does the author have evidence for the given facts?

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Ones you add if you wanted to is
Does the author give any sources? (Like where they got the info)

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