What mass of solid na2co3 is required to make 250.0ml of a 0.125m solution of na2co3?

If i initially have a gas at a pressure of 12 atm, a volume of 23 liters, and a temperature of 200 k, and then i raise the pressure to 14 atm and increase the temperature to 300 k, what is the new volume of the gas?

How many moles of lead are in 1.50 x 10^12 atoms of lead? could you explain the answer as well and not just give it to me i am refreshing for finals and i need to know how to do it

What happens to the temperature of a substance when the average kinetic energy of its particles increases?