The question seems to have a contradiction. You mentioned that the ratio of hydrogen to chlorine is 1:35, but then asked what mass of chlorine is needed when there are 25 g of chlorine available. If you already have 25 g of chlorine, you don’t need any additional chlorine.
However, if you’re asking how much hydrogen is needed to react with the 25 g of chlorine to produce hydrochloric acid, we can calculate that based on the given ratio.
In the formation of hydrochloric acid (HCl), the ratio of hydrogen (H) to chlorine (Cl) is 1:35 by mass. This means that for every 1 g of hydrogen, 35 g of chlorine is needed.
So, if you have 25 g of chlorine, you can calculate the amount of hydrogen needed using the ratio:
1 g of H : 35 g of Cl = x g of H : 25 g of Cl
Solving for x gives:
x = (1 g of H / 35 g of Cl) * 25 g of Cl = 0.714 g of H
So, you would need approximately 0.714 g of hydrogen to react with 25 g of chlorine to produce hydrochloric acid.