Can someone please help me?

Question

Using the balanced chemical equation: H2 + Cl2 → 2HCl How many grams of hydrochloric acid (HCl) are produced from 9.5 g of hydrogen (H2) reacting with excess chlorine?

Answer 1

H₂ + Cl₂ ==> 2HCl ... balanced equation

Since Cl₂ is present in excess, the final amount of HCl is dictated by the amount (moles) of H₂ present. In problems such as these, we always work in MOLES (not grams), and then at the end, convert back to grams.

moles H₂ present = 9.5 g H₂ x 1 mole H₂ / 2.02 g H₂ = 4.703 moles H₂

Now use the balanced equation to find moles of HCl produced:

moles HCl produced = 4.703 moles H₂ x 2 moles HCl / 1 mole H₂ = 9.406 moles of HCl produced

Finally, convert this to grams of HCl produced:

9.406 moles HCl x 36.46 g HCl / mole HCl = 342.9 g HCl

Rounding this answer to 2 significant figures (based on 2 s.f. in 9.5 g H2), we get

340 g HCl produced

Answer 2

Hello, thank you for taking the time to post your question!

First you want to convert the grams of H2 over into moles. That means taking

9.5 g / 2.016 g/mol = 4.712 mol H2

Then you can use the ratio of the coefficients to convert that over into moles of HCl

4.712 mol H2 x 2 mol HCl/1 mol H2 = 9.424 mol HCl

Finally then you want to multiply by the molar pass to get the grams of HCl

9.424 mol HCl x 36.46 g/mol = 343.6 g HCl

Meaning that around 343.6 grams of HCl are produced by this reaction

I hope that helps you get moving in a better direction on this type of question! Feel free to reach out if you have any additional questions beyond that :)