7.5 mol of hydrogen would be needed to consume the available nitrogen.
Explanation:
When hydrogen reacts with nitrogen, ammonia is formed as shown below;
3H₂ (g) + N₂ (g) → 2NH₃ (g)
As seen from the equation, every 3 moles of H₂ react with a mole of N₂ to form 2 moles of NH₃.
The limiting factor in a chemical reaction is the reactant that gets depleted first.
Because the molar mass of nitrogen gas is approximately 28g/mol, 70g of nitrogen gas would be 2.5 moles.
The reaction ratio of nitrogen to hydrogen in the reaction is 1 : 3. The reaction would require 2.5 * 3 (7.5) moles of hydrogen for a complete reaction.
However since there are only 7g on hydrogen, (Remember 1 mole of H₂ is approximately 2g), the available moles of H₂ is 7 / 2 = 3.5
3.5 moles fall short of the 7.5 moles of H₂ required for a complete reaction. H₂ gets depleted first before N₂. The reaction would require 4 more moles of H₂.
It’s kind of difficult to explain without being with you in person but try looking up videos on YouTube as they tend to be extremely helpful. Don’t give up on the videos right away though, keep watching it over and over until you understand. Also try to find a teacher or a smart friend to help to if you still don’t understand. I recommend getting a tutor if you require long term help. Best of luck in your studies!!
Generally speaking only certain molecules will dissolve in water to begin with. The old phrase "like dissolves like" or "birds of a feather flock together" is very true with respect to what degree solutes are soluble or miscible in different solvents. At very low concentrations, almost all molecules are somewhat soluble in all solvents. But by trend, ionic and polar solutes are more soluble in polar solvents and non-polar molecules are soluble in non-polar (mostly organic) solvents. The units of concentration we just discussed are used to describe the degree to which a solute is soluble in a solvent.
When you place a non-polar molecule in a polar solvent (like oil in water) the molecules try to minimize surface contact between them. (like you and a guy with a cold on an elevator). This is actually the basis for the cells in our bodies. The lipids (oily fatty acids) form our cell membranes so that their non-polar tails face inward away from the polar cytoplasm and the polar heads face towards the polar cytoplasm.
It’s called Avogadro’s number!
