What temperature in Celsius is 281 K

How does litmus paper indicate an acid?

At 450 mm hg a gas has a volume of 760 l, what is its volume at standard pressure

Need ! asap will mark 10 pts using the room temperature line (orange line) and your periodic table, make lists that identify the state of matter (gas, liquid, or solid) in which each element you plotted exists at room temperature. explain your answers