Which of the following sets of compounds DO NOT follow the law of multiple proportions?
a) NH3, H2O and NO2
b) NO, NO2 and N2O5
c) CO, CO2 and CH4
d) H2O, CO2 and CH4
Law of multiple proportions, statement that when two elements combine with each other to form more than one compound, the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers. ...
Read the law above carefully.
a) NH3, H2O and NO2
These are the SAME element
b) NO, NO2 and N2O5
N and O across the board. These are the same two elements combining with each other. b IS an example
c) CO, CO2 and CH4
CH4 keeps it from the same two elements.
d) H2O, CO2 and CH4
Not same two elements again.
b is an example that follows the law. a, c, d do not follow the law. But I have a problem with the question. a, c and d are not, in my opinion, examples of the law because a, c and d don't have the same two elements.
To determine which sets of compounds do not follow the law of multiple proportions, let's first understand what the law of multiple proportions states.
The law of multiple proportions, also known as Dalton's Law, states that when two elements combine to form different compounds, the ratio of the masses of one element that combine with a fixed mass of the other element can be expressed in small whole numbers. In other words, when two elements A and B combine to form multiple compounds, the ratios of the masses of A and B in these compounds will be simple whole number ratios.
Now, let's analyze each set of compounds provided and apply the law of multiple proportions:
a) NH3, H2O, and NO2:
- Nitrogen (N) has a molar mass of approximately 14 g/mol, and Hydrogen (H) has a molar mass of approximately 1 g/mol.
- In NH3 (ammonia), there is 1 Nitrogen atom and 3 Hydrogen atoms, which gives us a ratio of 1:3.
- In H2O (water), there is 1 Oxygen atom and 2 Hydrogen atoms, which gives us a ratio of 1:2.
- In NO2 (nitrogen dioxide), there is 1 Nitrogen atom and 2 Oxygen atoms, which gives us a ratio of 1:2.
All the ratios for each element in these compounds are simple whole number ratios, so this set follows the law of multiple proportions.
b) NO, NO2, and N2O5:
- Nitrogen (N) has a molar mass of approximately 14 g/mol and Oxygen (O) has a molar mass of approximately 16 g/mol.
- In NO (nitric oxide), there is 1 Nitrogen atom and 1 Oxygen atom, which gives us a ratio of 1:1.
- In NO2 (nitrogen dioxide), there is 1 Nitrogen atom and 2 Oxygen atoms, which gives us a ratio of 1:2.
- In N2O5 (dinitrogen pentoxide), there are 2 Nitrogen atoms and 5 Oxygen atoms, which gives us a ratio of 2:5.
The ratios for Nitrogen and Oxygen in these compounds are not simple whole numbers, so this set does not follow the law of multiple proportions.
c) CO, CO2, and CH4:
- Carbon (C) has a molar mass of approximately 12 g/mol and Oxygen (O) has a molar mass of approximately 16 g/mol. Hydrogen (H) has a molar mass of approximately 1 g/mol.
- In CO (carbon monoxide), there is 1 Carbon atom and 1 Oxygen atom, which gives us a ratio of 1:1.
- In CO2 (carbon dioxide), there is 1 Carbon atom and 2 Oxygen atoms, which gives us a ratio of 1:2.
- In CH4 (methane), there is 1 Carbon atom and 4 Hydrogen atoms, which gives us a ratio of 1:4.
All the ratios for each element in these compounds are simple whole number ratios, so this set follows the law of multiple proportions.
d) H2O, CO2, and CH4:
- Hydrogen (H) has a molar mass of approximately 1 g/mol, Carbon (C) has a molar mass of approximately 12 g/mol, and Oxygen (O) has a molar mass of approximately 16 g/mol.
- In H2O (water), there is 2 Hydrogen atoms and 1 Oxygen atom, which gives us a ratio of 2:1.
- In CO2 (carbon dioxide), there is 1 Carbon atom and 2 Oxygen atoms, which gives us a ratio of 1:2.
- In CH4 (methane), there is 1 Carbon atom and 4 Hydrogen atoms, which gives us a ratio of 1:4.
All the ratios for each element in these compounds are simple whole number ratios, so this set follows the law of multiple proportions.
Based on our analysis, the sets of compounds that do not follow the law of multiple proportions are:
b) NO, NO2, and N2O5