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4 years ago

Please help with chemistry work

Chemistry

1 answer:

Andrei [34K]4 years ago

5 0

Answer:

Explanation:

14:

a) Shared pairs = 6

per shared pair between each C-H bond.

and two shared pair between C=C thus total shared pairs are 6

a) Lone pairs = 0

b) Single bonds = 4

Double bonds = 1

Triple bonds = 0

c) Formula = C₂H₄

Name = Ethene

d) Lewis structure = given structure is also Lewis structure.

13:

a) Shared pairs = 3

a) Lone pairs = 2

b) Single bonds = 0

Double bonds = 0

Triple bonds = 1

c) Formula = N₂

Name = Dinitrogen

d) Lewis structure = given structure is also Lewis structure.

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The primary method in which two connected objects transfer energy by heat flow is _____.

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3 years ago

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How many equivalents are in a solution that contains 0.25 moles Mg2+ and 0.50 moles Cl–?

Vinil7 [7]

Answer:

Explanation:

Mg²⁺ is divalent , hence

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3 years ago

How many moles are represented by 3.01 x10^24 oxygen atoms?

asambeis [7]

<h3>Answer:</h3>

5.00 mol O₂

<h3>General Formulas and Concepts:</h3>

<u>Pre-Algebra</u>

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right<u> </u>

<u>Chemistry</u>

<u>Atomic Structure</u>

Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.<u> </u>

<u>Stoichiometry</u>

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<h3>Explanation:</h3>

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3.01 × 10²⁴ atoms O₂

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Set up: $\displaystyle 3.01 \cdot 10^{24} \ atoms \ O_2(\frac{1 \ mol \ O_2}{6.022 \cdot 10^{23} \ atoms \ O_2})$
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3 years ago

9. Sodium reacts with water to produce sodium hydroxide and hydrogen gas, as shown below.

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3 years ago

Calculate the theoretical yield of aspirin obtained when 2.0 g of salicylic acid and 5.0 mL of acetic anhydride (density = 1.08

saw5 [17]

Answer:

The percent yield would be 73%

Explanation:

The balanced reaction for the obtention of acetylsalicylic acid (aspirin) is the following:

Salicylic acid + acetic anhydride → acetylsalicylic acid + acetic acid

C₇H₆O₃ + C₄H₆O₃ → C₉H₈O₄ + C₂H₄O₂

According to the reaction, 1 mol of salicylic acid reacts with 1 mol of acetic anhydride to give 1 mol of acetylsalicylic acid (aspirin) and 1 mol of acetic acid.

1 mol aspirin (C₉H₈O₄) = (9 x 12 g/mol) + (8 x 1 g/mol) + (4 x 16 g/mol)

= 180 g

1 mol salicylic acid (C₇H₆O₃) = (7 x 12 g/mol) + (6 x 1 g/mol) + (3 x 16 g/mol)

= 138 g

1 mol acetic anhydride (C₄H₆O₃) = (4 x 12 g/mol) + (6 x 1 g/mol) + (3 x 16 g/mol)

= 102 g

The stoichiometric ratio is = 138 g salicylic acid/102 g acetic anhydride= 1.35

We have:

2.0 g salicylic acid

acetic anhydride = 5.0 mL x 1.08 g/mL = 5.4 g

The reactants ratio is = 2.0 g salicylic acid/5.4 g acetic anhydride = 0.37

0.37 < 1.35 , therefore <em>salicylic acid is the limiting reactant</em>.

Now, we use the amount of salicylic acid to calculate the theoretical amount of aspirin. For this, we know that 1 mol of aspirin (180 g) is obtained from 1 mol of salycilic acid (138 g):

theoretical yield= 180 g aspirin/138 g salycilic acid x 2.0 g salycilic acid = 2.61 g aspirin

actual yield = 1.9 g

Finally, we calculate the yield:

percent yield = actual yield/theoretical yield x 100

= 1.9 g/2.6 g x 100 = 72.8% ≅ 73%

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3 years ago