Helium,it has an atomic mass of 4,which means total no. of protons and neutrons,so I think you meant 2 protons and an atomic mass of 4
There are a couple of ways in which you can express the concentration of a solution, and here they are: gram per liter (g/L), molarity (M), parts per million (ppm.), and percents (%).
As you can see, only M appears in your answers, which means that the correct option should be (2) 3.5 M.
The answer is a because the water we use it comes back again
The mole fraction of a product is the number of moles of the product divided by the total number of moles of the solution.
Here moles of methanol = 6.0 moles
Moles of solution = 6.0 moles of methanol + 3.0 moles of water = 9.0 moles of solution
Mole fraction of methanol = 6.0 / 9.0 = 0.67
Answer: 0.67