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3 years ago

4.2g of sodium bicarbonate is equivalent to how many moles of sodium bicarbonate

2 answers:

7 0

<span>The mass of one mole of sodium bicarbonate (aka NaHCO3) is equal to 1 * 22.99g/mol + 1 * 1.00g/mol + 1 * 12.01g/mol + 3 * 16.00g/mol = 83.91g/mol. From this, we can convert 4.2g of NaHCO3 to moles by dividing by 83.91g/mol, to get 0.050 moles of sodium bicarbonate.</span>

babunello [35]3 years ago

7 0

<u>Answer:</u> The number of moles of sodium bicarbonate are 0.05 moles.

<u>Explanation:</u>

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

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

Given mass of sodium bicarbonate = 4.2 g

Molar mass of sodium bicarbonate = 84 g/mol

Putting values in above equation, we get:

$\text{Moles of sodium bicarbonate}=\frac{4.2g}{84g/mol}=0.05mol$

Hence, the number of moles of sodium bicarbonate are 0.05 moles.

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As,

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Explanation:

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As, for reversible isothermal expansion the formula is as follows.

W = $-2.303 nRT log(\frac{V_2}{V_1})$

Since, we are not given the number of moles here. Therefore, we assume the number of moles, n = 1 mol.

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W = $-2.303 nRT log(\frac{V_2}{V_1})$

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Step 1: When there is no change in volume then W = 0

Hence, for step 1, W = 0

Step 2: As, the gas is allowed to expand against constant external pressure $P_{external}$ = 1.00 atm.

So, W = $-P_{external} \times \Delta V$

Now, putting the given values into the above formula as follows.

W = $-P_{external} \times \Delta V$

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Hence, work will be calculated as follows.

W = $-\frac{101.33 J}{1 atm L} \times 5.67 atm L$

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Therefore, total work done by path B = 0 + (-574.54 J)

W = -574.54 J

Hence, work for path B is -574.54 J.

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<h3>Further explanation</h3>

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Required

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