Final answer:
To double the volume and pressure of a gas at 273K, it must be heated to 546K.
Step-by-step explanation:
According to Charles's law in gas laws, the volume of a gas is directly proportional to its temperature, assuming constant pressure. So, to double the volume of the gas, we need to double its temperature. Therefore, the gas must be heated to 546K (273K*2) in order to double its volume and pressure.