Determine the theoretical yield of zinc chloride .4g zinc 6m hcl
The correct answer and explanation is:
To determine the theoretical yield of zinc chloride (ZnCl₂) from 0.4 g of zinc (Zn) reacting with 6 M hydrochloric acid (HCl), we first need the balanced chemical equation and then apply stoichiometry.
✅ Balanced Chemical Equation:
Zn (s)+2HCl (aq)→ZnCl2(aq)+H2(g)\text{Zn (s)} + 2\text{HCl (aq)} \rightarrow \text{ZnCl}_2\text{(aq)} + \text{H}_2\text{(g)}
✅ Step 1: Calculate moles of zinc used
Atomic mass of Zn=65.38 g/mol\text{Atomic mass of Zn} = 65.38 \, \text{g/mol} Moles of Zn=0.4 g65.38 g/mol≈0.00612 mol\text{Moles of Zn} = \frac{0.4 \, \text{g}}{65.38 \, \text{g/mol}} \approx 0.00612 \, \text{mol}
✅ Step 2: Use molar ratio to find moles of ZnCl₂
From the balanced equation: 1 mol Zn→1 mol ZnCl2\text{1 mol Zn} \rightarrow 1 \text{ mol ZnCl}_2
So, Moles of ZnCl2=0.00612 mol\text{Moles of ZnCl}_2 = 0.00612 \, \text{mol}
✅ Step 3: Convert moles of ZnCl₂ to grams
Molar mass of ZnCl2=65.38+(35.45×2)=136.28 g/mol\text{Molar mass of ZnCl}_2 = 65.38 + (35.45 × 2) = 136.28 \, \text{g/mol} Mass of ZnCl2=0.00612×136.28≈0.834 g\text{Mass of ZnCl}_2 = 0.00612 \times 136.28 \approx 0.834 \, \text{g}
✅ Final Answer:
Theoretical yield of zinc chloride = 0.834 g
✍️ Explanation (Approx. 300 Words):
The theoretical yield represents the maximum amount of product that can be formed from a given amount of reactants, assuming perfect conditions and complete reaction. In this case, we are calculating how much zinc chloride (ZnCl₂) can be produced from 0.4 grams of zinc using 6 M hydrochloric acid.
We begin with the balanced chemical equation: Zn+2HCl→ZnCl2+H2\text{Zn} + 2\text{HCl} \rightarrow \text{ZnCl}_2 + \text{H}_2
This shows that 1 mole of zinc reacts with 2 moles of hydrochloric acid to produce 1 mole of zinc chloride. Since we have an excess of HCl (as 6 M is highly concentrated), zinc is the limiting reactant—it determines how much ZnCl₂ can be made.
Next, we convert 0.4 grams of zinc to moles using its atomic mass (65.38 g/mol). This gives us approximately 0.00612 mol of zinc. Because the molar ratio of Zn to ZnCl₂ is 1:1, we expect to form 0.00612 mol of ZnCl₂.
To find the mass of zinc chloride produced, we multiply the moles of ZnCl₂ by its molar mass, which is 136.28 g/mol. This results in a theoretical yield of about 0.834 grams of ZnCl₂.
This calculation is vital in chemistry labs to predict the efficiency of a reaction and compare it with the actual yield to determine percent yield.