Mrs. Rushing fills a balloon with hydrogen gas to demonstrate its ability to burn. Which combination could she

Find the molarity of 186.55 g of sugar (C12H22O11) in 250. mL of water.

Anna [14]

Answer:

The molarity of this sugar solution in water is 2.18 M

Explanation:

Step 1: Data given

Mass of sugar (C12H22O11) = 186.55 grams

Molar mass of C12H22O11 = 342.3 g/mol

Volume of water = 250.0 mL = 0.250 L

Step 2: Calculate moles sugar

Moles sugar = mass sugar / molar mass sugar

Moles sugar = 186.55 grams / 342.3 g/mol

Moles sugar = 0.545 moles

Step 3: Calculate molarity of the sugar solution

Molarity = moles sugar / volume of water

Molarity = 0.545 moles / 0.250 L

Molarity = 2.18 MThe molarity of this sugar solution in water is 2.18 M

6 0

2 years ago

A 8.6 g sample of methane and 15.6 g sample of oxygen react according to the reaction in the video. identify the limiting reacta

GalinKa [24]

Answer:

23.6 g carbon dioxide comes from 8.6 g of CH4 or 10.7 g carbon dioxide comes from 15.6 g O that means the 15.6 g of oxygen is still the limiting reactant because it gets used up and only makes 10.7 g of CO2. 

Explanation:

1) Balanced chemical equation:

CH₄ + 2O₂ → CO₂ + 2H₂O

2) mole ratios:
1 mol CH₄ : 2mol O₂ : 1 mol CO₂ : 2 mol H₂O

3) molar masses
CH₄: 16.04 g/mol
O₂: 32.0 g/mol
CO₂: 44.01 g/mol

4) Convert the reactant masses to number of moles, using the formula

number of moles = mass in grams / molar mass

CH₄: 8.6g / 16.04 g/mol = 0.5362 moles


O₂: 15.6 g / 32.0 g/mol = 0.4875 moles

5) If the whole 0.5632 moles of CH₄ reacted that yields to the same number of moles of CO₂ and that is a mass of:
mass of CO₂ = number of moles x molar mass = 23.60 g of CO₂

Which is what the first part of the answer says.

6) If the whole 0.4875 moles of O₂ reacted that would yield 0.4875 / 2 = 0.24375 moles of CO₂, and that is a mass of:
mass of CO₂ = 0.4875 grams x 44.01 g/mol = 10.7 grams of CO₂.

Which is what the second part of the answer says.

7) From the mole ratio you know infere that 0.5362 moles of CH₄ needs more twice number of moles of O₂, that is 1.0724 moles of O₂, and since there are only 0.4875 moles of O₂, this is the limiting reactant.

Which is what the chosen answer says.

8) From the mole ratios 0.4875 moles of O₂ produce 0.4875 / 2 moles of CO₂, and that is:
0.4875 / 2 mols x 44.01 g/mol = 10.7 g of CO₂, which is the last part of the answer.

3 0

2 years ago

A student dissolved a sample in hexane, spotted it on to a TLC plate and eluted using ethyl acetate. After visualizing the TLC p

Zepler [3.9K]

1) Consider the following silica gel TLC plate of compounds A, B, and C developed in hexanes:

Determine the Rf values of compounds A, B, and C run on a silica gel TLC plate using hexanes as the solvent.Which compound, A, B, or C, is the most polar?What would you expect to happen to the Rf values if you used acetone instead of hexanes as the eluting solvent?How would the Rf values change if eluted with hexanes using an alumina TLC plate?

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2) You are trying to determine a TLC solvent system which will separate the compounds X, Y, and Z. You ran the compounds on a TLC plate using hexanes/ethyl acetate 95:5 as the eluting solvent and obtained the chromatogram below. How could you change the solvent system to give better separation of these three compounds?

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3) After a rather lengthy organic chemistry synthesis procedure, a student ran the product of the reaction on a TLC plate and obtained the result below. What might he/she have done wrong, if anything?

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4) A student spots an unknown sample on a TLC plate. After developing in hexanes/ethyl acetate 50:50, he/she saw a single spot with an Rf of 0.55. Does this indicate that the unknown material is a pure compound? What can be done to verify the purity of the sample?

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5) Consider a sample that is a mixture composed of biphenyl, benzoic acid, and benzyl alcohol. The sample is spotted on a TLC plate and developed in a hexanes/ethyl acetate solvent mixture. Predict the relative Rf values for the three compounds in the sample.

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6) Plate A, below, represents the TLC chromatogram of a compound run in hexanes. The same compound was then spotted on a large TLC plate and again run in hexanes. Which TLC plate, B, C, or D, correctly represents how far the compound would run on the longer plate?

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The information on these pages is available for academic use without restriction.

3 0

2 years ago

When magnesium ribbon is placed in sulfuric acid, a chemical reaction takes place and heat energy is given off. Liang and Naraba

kolezko [41]

Answer:

this is the answer

I hope it helps you although