Answer:
The actual value = 25.7 ml
The error = 15.6%
This means that the value of error = 0.156 * 25.7 = 4.0092 ml
Now, the error percentage found means that the student got the value either greater than the actual one with the value of error or less than the actual one with the value of error.
This means that the two possible readings are:
either : 25.7 + 4.0092 = 29.7092 ml
or : 25.7 - 4.0092 = 21.6908 ml
Explanation:
Answer:
- <em>Option d. Its empirical formula is CH</em><em>₂</em><em>.</em>
Explanation:
The percent composition of the compound allow you to calculate the empirical formula of the compound but is not enough to calculate either the molar mass or the molecular formula. So, since now you can discard options b. and c.
Telling that it is a hydrocarbon (option e.) is true but very vague compared with finding the empirical formula. So, you can also discard the option e.
The fact that the product has a triple bond cannot be concluded from the percent composition, you should find the molecular formula to assert whether it contains or not a triple bond. So, you could discard option a., which lets you only with choice d.
Let us find the empirical formula to be certain that it is CH₂.
1. <u>First, assume a basis of 100 g of compound</u>:
- H: 14.5% × 100 g = 14.0 g
- C: 85.5% × 100 g = 85.5 g
2. <u>Divide each element by its atomic mass to find number of moles</u>:
- H: 14.0 g / 1.008 g/mol = 14.38 mol
- C: 85.5 g / 12.011 g/mol = 7.12 mol
3. <u>Divide both amounts by the smallest number, to find the mole ratio</u>:
- H: 14.38 mol / 7.12 mol ≈ 2
- C: 7.12 mol / 7.12 mol = 1.
Hence, the ratio is 2:1 and the empirical formula is CH₂.
Amu valie on the top and abundsnce percent in decimals on the bottom for each isotope
<span>1.23x10^24 atoms/6.022x10^23 atom/mol = 2.04 mol H20 </span>
