section 3.4 continued\n18. sucrose is 51.50% oxygen. how many grams of oxygen are in 20.0 g of sucrose? show…
section 3.4 continued\n18. sucrose is 51.50% oxygen. how many grams of oxygen are in 20.0 g of sucrose? show your work.\n19. a 2 - g sample of sucrose is 6.50% hydrogen. what is the mass percentage of hydrogen in 300 g of sucrose? explain your reasoning.\n20. two compound samples are found to have the same mass percentages of the same elements. what can you conclude about the two samples?\nin your textbook, read about the law of multiple proportions.\nuse the law of multiple proportions to answer the questions and complete the table below.\nthe law of multiple proportions states that if the elements x and y form two compounds, the different masses of y that combine with a fixed mass of x can be expressed as a ratio of small whole numbers.\n21. two compound samples are composed of the same elements, but in different proportions. what can you conclude about the two samples?\nfor each compound in the table, fill in the ratio of the mass of oxygen to the mass of hydrogen.\n| compound | mass of oxygen | mass of hydrogen | mass o/mass h |\n| ---- | ---- | ---- | ---- |\n| h₂o | 16 g | 2 g | 22. |\n| h₂o₂ | 32 g | 2 g | 23. |\n24. write a brief statement comparing the two mass ratios from the table.\n25. are h₂o and h₂o₂ the same compound? explain your answer.
Answer
18.
Explanation:
Step1: Identify the formula
We use the formula: Mass of element = Percentage of element×Mass of compound.
Step2: Substitute values
The percentage of oxygen is 51.50% or 0.515 in decimal - form, and the mass of sucrose is 20.0 g. So, Mass of oxygen = 0.515×20.0 g.
Step3: Calculate the result
0.515×20.0 = 10.3 g.
Answer:
10.3 g
19.
Brief Explanations:
The mass - percentage of an element in a pure compound is a characteristic property and does not depend on the amount of the compound. Sucrose is a pure compound, so the mass - percentage of hydrogen in any amount of sucrose is the same.
Answer:
6.50%
20.
Brief Explanations:
If two compound samples have the same mass percentages of the same elements, they may be the same compound. This is because the mass - percentage composition is a characteristic property of a pure compound.
Answer:
They may be the same compound.
21.
Brief Explanations:
When two compound samples are composed of the same elements but in different proportions, they are different compounds. This is in accordance with the law of multiple proportions.
Answer:
They are different compounds.
22.
Explanation:
To find the ratio of the mass of oxygen to the mass of hydrogen in H₂O, we divide the mass of oxygen by the mass of hydrogen. Mass of oxygen = 16 g, mass of hydrogen = 2 g. Ratio = $\frac{16}{2}$ = 8.
Answer:
8
23.
Explanation:
To find the ratio of the mass of oxygen to the mass of hydrogen in H₂O₂, we divide the mass of oxygen by the mass of hydrogen. Mass of oxygen = 32 g, mass of hydrogen = 2 g. Ratio = $\frac{32}{2}$ = 16.
Answer:
16
24.
Brief Explanations:
The ratio of the mass of oxygen to the mass of hydrogen in H₂O is 8, and in H₂O₂ is 16. The ratio of the two ratios (16:8) simplifies to 2:1, which is a ratio of small whole numbers as stated in the law of multiple proportions.
Answer:
The ratio of the mass of oxygen to hydrogen in H₂O₂ is twice that in H₂O, and the ratio of these two ratios (16:8) is 2:1, a ratio of small whole numbers.
25.
Brief Explanations:
H₂O and H₂O₂ are not the same compound. They have different chemical formulas, which means they have different arrangements of atoms and different chemical and physical properties. Also, the ratio of oxygen to hydrogen is different in each compound.
Answer:
No, they are not the same compound. They have different chemical formulas and different mass - ratios of oxygen to hydrogen.