A given amount of gas occupies 10.0dm5 at 4atm and 273°C. The number of moles of...

To solve this question, we'll use the Ideal Gas Law, which is given by the formula:

\[PV = nRT\]

Where P is pressure, V is volume, n is the number of moles, R is the gas constant, and T is temperature in Kelvin.

First, let's convert the given temperature from Celsius to Kelvin:

\[T = 273 + 273 = 546\,\text{K}\]

Next, we'll use the given values and the Ideal Gas Law to find the number of moles:

\[4\,\text{atm} \times 10\,\text{dm}^3 = n \times 0.0821\,\frac{\text{atm}\cdot\text{dm}^3}{\text{mol}\cdot\text{K}} \times 546\,\text{K}\]

Solve for n:

\[n = \frac{4\,\text{atm} \times 10\,\text{dm}^3}{0.0821\,\frac{\text{atm}\cdot\text{dm}^3}{\text{mol}\cdot\text{K}} \times 546\,\text{K}} \approx 0.89\,\text{mol}\]

Therefore, the number of moles of the gas present is approximately 0.89 mol, which corresponds to Option A.