Sulfur forms two compounds with fluorine, T and U. Compound T has 0.447 g of sulfur combined with 1.06 g of fluorine; compound U has 0.438 g of sulfur combined with 1.56 g of...

Sulfur forms two compounds with fluorine, T and U. Compound T has 0.447 g of sulfur combined with 1.06 g of fluorine; compound U has 0.438 g of sulfur combined with 1.56 g of fluorine. Show that these data support the law of multiple proportions. Essay answers are limited to about 500 words

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justaguide | College Teacher | (Level 2) Distinguished Educator

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When chemical elements combine with each other to form compounds they do so in a ratio of small whole numbers. This is known as the law of multiple proportions and was put forth by John Dalton in 1803.

Sulfur and fluorine combine with each other to form two compounds T and U. Compound T has 0.447 g of sulfur and 1.06 g of fluorine, compound U has 0.438  g of sulfur combined with 1.56 g of fluorine.

The atomic mass of sulfur is 32.065 and the atomic mass of fluorine is 18.99.

0.447 g of sulfur is equivalent to 0.0139 mole of sulfur and 1.06 g of fluorine is equivalent to 0.0558 mole of fluorine. The ratio in which the two combine in T is 1 : 4. 0.438  g of sulfur is equivalent to 0.0136 moles of sulfur and 1.56 g of fluorine is equivalent to 0.082 moles of fluorine. The ratio of the elements in this case is 1 : 6

This shows the law of multiple proportions is being followed as the ratio is that of small whole numbers.

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science2014 | (Level 1) Valedictorian

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By dividing each mass with the respective atomic weight, we obtain the number of moles of each element.
For compound T:
S = 0.447 / 32.07 = 13.9 moles
F = 1.06 / 19.00 = 55.8 moles
So molar ratio: 55.8 / 13.9 = 4
Compound T is SF4, sulfur tetrafluoride

For compound U:
S = 0.438 / 32.07 = 13.66 moles
F = 1.56 / 19.00 = 82.1 moles
So molar ratio: 82.1 / 13.66 = 6
Compound U is SF6, sulfur hexafluoride

This data supports law of multiple proportion, as the elements are combining in the ratio of smallest whole numbers.

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nav1996 | Student | (Level 1) Honors

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First, we need to find the number of moles of Sulfur and Fluorine found in each compound. 

Compound T:

0.447g/32.1g/mol = 0.014 moles of Sulfur

1.06g/18.99g/mol = 0.056 moles of Fluorine

You can then divide both these numbers by the smaller quantity in order to obtain a ratio of the number of moles present of each element. In this case, the number with which to divide would be 0.014.

0.014/0.014 = 1 mole of Sulfur

0.056/0.014 = 4 moles of Fluorine

Thus, the compound is SF4

The same procedure can be applied to Compound U:

0.438g/32.1g/mol = 0.014 moles of Sulfur

1.56g/18.99g/mol = 0.082 moles of Fluorine

Again, we can divide by the smaller number to find the ratio of the elements.

0.014/0.014 = 1 mole of Sulfur

0.082/0.014 = 6 moles of Fluorine

Thus, the compound is SF6.

This displays the rule of multiple proportions as it shows that compounds can form in simple whole-number ratio as well as the fact that elements can combine together in more than one way. 

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