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3 years ago

Part A

Chemistry

2 answers:

Harrizon [31]3 years ago

5 0

Answer:

C₂H₅O₂

Explanation:

The empirical formula, is the reduced formula of a compound, with the elements followed by its smallest possible number of moles.

First, let's calculated the number of moles of each element. The molar masses are:

C = 12 g/mol, H = 1 g/mol, O = 16 g/mol

The number of moles is the mass divided by molar mass, so :

nC = 330/12 = 27.5

nH = 69.5/1 = 69.5

nO = 440.4/16 = 27.5

To have the empirical formula, let's divide all the number of moles for the smallest: 27.5

nC = 27.5/27.5 = 1

nH = 69.5/27.5 = 2.5

nO = 27.5/27.5 = 1

The empirical formula can't have fractional numbers, so let's multiply all the numbers for 2

nC = 2

nH = 5

nO = 2

The empirical formula is

C₂H₅O₂

Colt1911 [192]3 years ago

3 0

I got this. I hope this helps. :/

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3 years ago

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UNO [17]

<u>Answer:</u> The enthalpy change of the reaction is -361.6 kJ

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To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

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When heat is absorbed by the solution, this means that heat is getting released by the reaction.

<u>Sign convention of heat:</u>

When heat is absorbed, the sign of heat is taken to be positive and when heat is released, the sign of heat is taken to be negative.

For the given chemical reaction:

$2Na(s)+2H_2O(l)\rightarrow NaOH(aq.)+H_2(g)$

When 0.025 moles of sodium is reacted, the heat released by the reaction is 4.52 kJ

So, when 2 moles of sodium will react, the heat released by the reaction will be = $\frac{4.52}{0.025}\times 2=361.6kJ$

Hence, the enthalpy change of the reaction is -361.6 kJ

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3 years ago

The reaction 2a → a2 was experimentally determined to be second order with a rate constant, k, equal to 0.0265 m–1min–1. if

olga nikolaevna [1]

According to the second order formula:
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3 years ago

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<h2>Answer 3:</h2>

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3 years ago

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Gnesinka [82]

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3 years ago