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4 years ago

Chem. Assignment I need help...with answers 1-6 thanks

Chemistry

1 answer:

Anna11 [10]4 years ago

8 0

Answer:

1. an educated guess

2. data

3. what changes in experiment

4. what stays the same in both groups

5. the group where nothing changes, normal

6. group with independent variable, what's being tested

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For the reaction ? Fe+? H2o ⇀↽? Fe3o4+? H2 , a maximum of how many grams of fe3o4 could be formed from 354 g of fe and 839 g of

Evgesh-ka [11]

The given reaction is:

3Fe + 4H2O → Fe3O4 + 4H2

Given:

Mass of Fe = 354 g

Mass of H2O = 839 g

Calculation:

Step 1 : Find the limiting reagent

Molar mass of Fe = 56 g/mol

Molar mass of H2O = 18 g/mol

# moles of Fe = mass of Fe/molar mass Fe = 354/56 = 6.321 moles

# moles of H2O = mass of h2O/molar mass of H2O = 839/18 = 46.611 moles

Since moles of Fe is less than H2O; Fe is the limiting reagent.

Step 2: Calculate moles of Fe3O4 formed

As per reaction stoichiometry:

3 moles of Fe form 1 mole of Fe3O4

Therefore, 6.321 moles of Fe = 6.321 * 1/ 3 = 2.107 moles of Fe3O4

Step 4: calculate the mass of Fe3O4 formed

Molar mass of Fe3O4 = 232 g/mol

# moles = 2.107 moles

Mass of Fe3O4 = moles * molar mass

= 2.107 moles * 232 g/mol = 488.8 g (489 g approx)

7 0

4 years ago

Read 2 more answers

b) 2C2H2(g) + 5O2(g)⟶4CO2(g) + 2H2O(l) 6.54 Calculate the heats of combustion for the following reactions from the standard enth

IRINA_888 [86]

Answer:

a. ΔH⁸ = -1420 kJ/mol b. ΔH⁸ = -1144.84 kJ/mol

Explanation:

C₂H₄ (g) + 3 O₂ (g) ------------------------ 4 CO₂ (g) + 2 H₂O (l) ΔH⁸ = ?

ΔH⁸f kJmol 52.47 0 -399.5 -285.83

ΔH⁸ = 2(-399.5) + 2 (-285.83) - (52.47)

ΔH⁸ = -1420 kJ/mol

H₂S (g) + 3 O₂ (g) ---------------------- 2 H₂O (l) + 2 SO₂ (g)

ΔH⁸f kJmol -20.50 0 -285.83 -296.84

ΔH⁸ = 2(-285.83) + 2 (-296.84) - (-20.50)

ΔH⁸ = -1144.84 kJ/mol

4 0

3 years ago

Consider stoichiometric combustion of gasoline and air. Assume a full tank of gasoline holds 50 L (approximately 13.2 gallons),

Inessa05 [86]

Answer:

520 kg

Explanation:

Let's consider the combustion of isooctane.

C₈H₁₈(l) + 12.5 O₂(g) → 8 CO₂(g) + 9 H₂O(l)

We can establish the following relations:

1 mL of C₈H₁₈ has a mass of 0.690 g (ρ = 0.690 g/mL).
The molar mass of C₈H₁₈ is 114.22 g/mol.
The molar ratio of C₈H₁₈ to O₂ is 1:12.5.
The mole fraction of O₂ in air is 0.21.
The molar mass of air is 28.96 g/mol.

50 L of isooctane require the following mass of air.

$50 \times 10^{3}mLC_{8}H_{18}.\frac{0.690gC_{8}H_{18}}{1mLC_{8}H_{18}} .\frac{1molC_{8}H_{18}}{114.22gC_{8}H_{18}} .\frac{12.5molO_{2}}{1molC_{8}H_{18}} .\frac{1molAir}{0.21molO_{2}} .\frac{28.96 \times 10^{-3}kgAir}{1molAir} =520kgAir$

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4 years ago

Ozone is produced by incomplete burning of fuels combustion of sulfur containing fuel decaying organic matter photochemical oxid

VARVARA [1.3K]

Ncomplete combustion of fossil fuels; forest fires// heavy traffic ... NS: oxidation of H2S gasfrom decay of organic matter & volcanic activity ... primary pollutant; burning of sulfur containingfossil fuels, coal containing ... HS: combustion of fossil fuel, industrial plants that produce smoke, ash, dust ..... photochemical smog.

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4 years ago

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When making a guess and Retesting This information, a model or______________ may be formed which explains why something has occu

iVinArrow [24]

Experiment

When making a guess and retesting this information, a model or experiment may be formed which explains why something has occured or what it may look like.

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3 years ago

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