A compound is 19.3% Na, 26.9% S, and 53.8% 0. Its formula mass is
238 g. What is its molecular formula?

A100-watt light bulb radiates energy at a rate of 100 j/s. (the watt, a unit of power or energy over time, is defined as 1 j/s.) if all of the light emitted has a wavelength of 525 nm , how many photons are emitted per second?

Given the following equation: 2a1 + 3mgcl2 --> 2alcl3 + 3mg how many moles of aluminum chloride are produced from 2.5 moles of magnesium chloride?

What is the approximate vapor pressure when the gas condenses at 70 degrees celsius