Placing a sample of iron (II) oxide into a graduated cylinder makes the water volume increase 12.0 mL. The weight of the sample
2 answers:
Answer:
Density,
Explanation:
It is given that, placing a sample of iron (II) oxide into a graduated cylinder makes the water volume increase 12.0 mL.
It means that the volume of the sample is 12 mL
The weight of the sample is 76.6 g
We need to find the density of the sample.
12 mL = 12 cm³
The formula of density is given by :
So, the density of the sample is .
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<h2>Hello!</h2>
The answer is:
The percent yield of the reaction is 32.45%
<h2>Why?</h2>To calculate the percent yield, we have to consider the theoretical yield and the actual yield. The theoretical yield as its name says is the yield expected, however, many times the difference between the theoretical yield and the actual yield is notorious.
We are given that:
Now, to calculate the percent yield, we need to divide the actual yield by the theoretical and multiply it by 100.
So, calculating we have:
Hence, we have that the percent yield of the reaction is 32.45%.
Have a nice day!
Answer:
8.61 mL of the HCl solution
Explanation:
The reaction that takes place is:
- 2HCl + Mg(OH)₂ → MgCl₂ + 2H₂O
From the given mass of Mg(OH)₂, we can calculate <u>the moles of HCl that are neutralized</u>:
- 4x10² mg = 400 mg = 0.400g
- 0.400g Mg(OH)₂ ÷ 58.32g/1mol = 6.859*10⁻³ mol Mg(OH)₂
- 6.859*10⁻³ mol Mg(OH)₂ *
3.429x10⁻³ mol HCl
Finally, to calculate the volume of an HCl solution, we need both the moles and the concentration. We can <u>calculate the concentration using the pH value</u>:
- pH = -log[H⁺]
- 1.4 = -log[H⁺]
= [H⁺]
- 0.0398 M = [H⁺] = [HCl] *Because HCl is a strong acid*
Thus, the volume is:
- 0.0398 M = 3.429x10⁻³mol HCl / Volume
- Volume = 8.616x10⁻³ L = 8.62 mL