Question

Please show all of your work! :)

Answer 1

Answer:

The problem says that carbon dioxide was collected at 740.4 mmHg, but this is a pressure that includes the pressure of the water. We want to only use the pressure of the carbon dioxide, so subtract the pressure of the water (21.0 mmHg) from 740.4 mmHg:

740.4 - 21.0 = 719.4 mmHg

Now, we can use the ideal gas law to find the number of moles of carbon dioxide we have: PV = nRT.

- the pressure P is 719.4 mmHg

- the volume V is 38.82 mL, but we need Litres, so divide 38.82 by 1000: 38.82 / 1000 = 0.03882 L

- the moles n is what we want to find

- the gas constant R is 62.36 L mmHg / (mol K)

- the temperature T is 23.0°C, but we need this in Kelvins, so add 273 to 23.0: 23.0 + 273 = 296 K

Plug all these in:

PV = nRT

(719.4 mmHg) * (0.03882 L) = n * (62.36) * (296 K)

n ≈ 0.00151 mol

Note that this is moles of carbon dioxide, but since we want CaCO3, we need to convert moles using the reaction. It's just a 1 to 1 ratio, so we still have 0.00151 moles of CaCO3. Now, convert moles to grams. The molar mass of CaCO3 is 40.08 + 12.01 + 3 * 16 = 100.09 g/mol.

To find the mass percent, divide 0.151 by the total mass of the tablet, which is 0.3211 g:

0.151 g / 0.3211 g = 0.471 = 47.1%

The Answer is D

Explanation:

Hope this help

Answer 2

Answer:

D

Explanation:

The problem says that carbon dioxide was collected at 740.4 mmHg, but this is a pressure that includes the pressure of the water. We want to only use the pressure of the carbon dioxide, so subtract the pressure of the water (21.0 mmHg) from 740.4 mmHg:

740.4 - 21.0 = 719.4 mmHg

Now, we can use the ideal gas law to find the number of moles of carbon dioxide we have: PV = nRT.

- the pressure P is 719.4 mmHg

- the volume V is 38.82 mL, but we need Litres, so divide 38.82 by 1000: 38.82 / 1000 = 0.03882 L

- the moles n is what we want to find

- the gas constant R is 62.36 L mmHg / (mol K)

- the temperature T is 23.0°C, but we need this in Kelvins, so add 273 to 23.0: 23.0 + 273 = 296 K

Plug all these in:

PV = nRT

(719.4 mmHg) * (0.03882 L) = n * (62.36) * (296 K)

n ≈ 0.00151 mol $CO_2$

Note that this is moles of carbon dioxide, but since we want CaCO3, we need to convert moles using the reaction. It's just a 1 to 1 ratio, so we still have 0.00151 moles of CaCO3. Now, convert moles to grams. The molar mass of CaCO3 is 40.08 + 12.01 + 3 * 16 = 100.09 g/mol.

$0.00151 molCaCO_3*\frac{100.09g}{1mol} =0.151gCaCO_3$

To find the mass percent, divide 0.151 by the total mass of the tablet, which is 0.3211 g:

0.151 g / 0.3211 g = 0.471 = 47.1%

The answer is D.