Question

A sample of gas occupies 806 mL at 26 degrees c and 1 atm. Find the volume of the gas at STP

Answer 1

The standard temperature and pressure is 273 K and 1 atm. Since, pressure is not changed we can use Charle's law for the calculations.

Charle's law says "at a constant pressure, the volume of a fixed amount of gas is directly proportional to its absolute temperature".

V α T 

Where V is the volume and T is the temperature in Kelvin of the gas. We can use this for two situations as,
V₁/T₁ = V₂/T₂

V₁ = 806 mL
T₁ = 26 ⁰C = 299 K
V₂ = ? 
T₂ = 273 K

By applying the formula,
(806 mL / 299 K) = (V₂ / 273 K)

                       V₂ = 735. 91 mL

Hence, the answer is "a".