I have the mass of one element and the moles of a compound, How do I find the mass of it'd Product? [Zn + 2HCl = ZnCl2 + H2] (Slove for mass of ZnCl2)
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Zinc - .5 grams
HCl- .2 moles
Find the Mass of ZnCl2
This is a limiting reagent (LR) problem. You know that because amounts are given for BOTH reactants.
mols Zn = grams/atomic mass = ?
mols HCl = 0.2
Using the coefficients in the balanced equation, convert mols Zn to mols ZnCl2.
Do the same and convert mols HCl to mols ZnCl2
It is likely that the two values for mols ZnCl2 will not agree which means one of them is not correct; the correct value in LR problems is ALWAYS the smaller value and the reagent responsible for that is the LR.
Using the smaller value, convert mols ZnCl2 to grams ZnCl2 by g = mols ZnCl2 x molar mass ZnCl2 = ?
To find the mass of ZnCl2, we need to use the information about moles and the balanced chemical equation. Here are the steps to follow:
Step 1: Determine the molar mass of ZnCl2.
- Zn (atomic mass) = 65.38 g/mol
- Cl (atomic mass) = 35.45 g/mol
- For ZnCl2, the molar mass would be:
65.38 g/mol (Zn) + 2 * 35.45 g/mol (Cl) = 136.28 g/mol
Step 2: Identify the number of moles of ZnCl2 from the given moles of the compound.
- Assuming you have the moles of the compound, you mentioned it as "n moles."
- Use the balanced chemical equation to relate the moles of the compound to moles of ZnCl2.
- From the equation Zn + 2HCl = ZnCl2 + H2, we know that one mole of ZnCl2 is produced for every one mole of Zn reacted.
- Hence, the number of moles of ZnCl2 will be the same as the number of moles of the compound (n moles).
Step 3: Calculate the mass of ZnCl2.
- Multiply the number of moles of ZnCl2 (which is equal to n moles) by the molar mass of ZnCl2 obtained in Step 1:
Mass of ZnCl2 = n moles * 136.28 g/mol
By following these steps, you can find the mass of ZnCl2 based on the given moles of the compound.