Chemistry - Molecular formula

[Michael_Light]

Homework Statement

1)When 0.1mol of a hydride of nitrogen , Y, decomposes completely, it produces 0.3mol of gaseous elements. Y might be

A)NH₃
B)N₂H₄
C)N₂H₆
D)N₃H₆

2) Under the same conditions, 10cm³ of an oxide of nitrogen produces 10cm³ of nitrogen when reduced. The formula of the oxide could be

1. N₂O₅
2. N₂O
3. NO

A)Only 1 is correct
B)Only 1 and 2 are correct
C) only 2 and 3 are correct
D) 1,2 and 3 are correct

Homework Equations

The answer for both 1 and 2 is B.

The Attempt at a Solution

Can anyone help me with question 1 and 2? If possible please explain or show me the working on how to obtain the final answer. Cause i really blur... Thanks...

 

[Borek]

Start writing possible reaction equations.

 

[Michael_Light]

Start writing possible reaction equations.

What do you mean by possible equations? Can you solve 1 question for me so i can have 1 example to refer? ><

 

[Borek]

Reaction equations of decomposition reactions. For example:

2NH₃ -> N₂ + 3H₂

 

[DeeNos]

For question 1, the molecular formula for the hydride of nitrogen can be determined by using the mole ratio between the initial and final amounts of gas produced. Since 0.1mol of Y decomposes to produce 0.3mol of gaseous elements, the mole ratio is 1:3. This means that for every 1 mole of Y, 3 moles of gaseous elements are produced.

To determine the molecular formula, we need to consider the possible combinations of elements in the hydride of nitrogen.

A) NH3 - This contains 1 mole of nitrogen and 3 moles of hydrogen, which matches the mole ratio of 1:3. Therefore, this could be the correct answer.

B) N2H4 - This also contains 1 mole of nitrogen and 2 moles of hydrogen, which does not match the mole ratio of 1:3. Therefore, this is not the correct answer.

C) N2H6 - This contains 2 moles of nitrogen and 6 moles of hydrogen, which does not match the mole ratio of 1:3. Therefore, this is not the correct answer.

D) N3H6 - This contains 3 moles of nitrogen and 6 moles of hydrogen, which also matches the mole ratio of 1:3. Therefore, this could also be the correct answer.

Therefore, the possible answers for the molecular formula of Y are A) NH3 and D) N3H6.

For question 2, the formula of the oxide of nitrogen can be determined by using the volume ratio between the initial and final volumes of gas produced. Since 10cm3 of the oxide produces 10cm3 of nitrogen, the volume ratio is 1:1. This means that for every 1cm3 of the oxide, 1cm3 of nitrogen is produced.

To determine the formula, we need to consider the possible combinations of elements in the oxide of nitrogen.

1. N2O5 - This contains 2 moles of nitrogen and 5 moles of oxygen, which does not match the volume ratio of 1:1. Therefore, this is not the correct answer.

2. N2O - This also contains 2 moles of nitrogen and 1 mole of oxygen, which matches the volume ratio of 1:1. Therefore, this could be the correct answer.

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