Which of the following pairs of compounds can be used to illustrate the law of multiple proportion?
a) NH3 and NH4Cl
b) ZnO2 and ZnCl2
c) H2O and HCl
d) NO and NO2
Could you also briefly explain why, please. Thank you.
NO, and NO2. Law of Multiple Proportion: 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.
notice the subscripts on the O atom, small whole numbers...
Thank you. :)
The correct answer is d) NO and NO2.
The law of multiple proportions states that when two elements combine to form multiple compounds, the ratio of the masses of one element that combines with a fixed mass of the other element can be expressed in small whole numbers.
In the case of NO and NO2, both compounds contain nitrogen (N) and oxygen (O) but in different ratios. NO contains one nitrogen atom and one oxygen atom, while NO2 contains one nitrogen atom and two oxygen atoms.
The ratio of the masses of oxygen in these compounds is 1:2, or 1:1 (simplified). This exemplifies the law of multiple proportions since the ratio can be expressed as a small whole number.
To determine which pair of compounds can be used to illustrate the law of multiple proportions, we need to understand what the law of multiple proportions states. The law of multiple proportions states that when elements combine to form different compounds, the mass ratios of one element to another will always be in small whole number ratios.
Now, let's analyze each pair of compounds:
a) NH3 and NH4Cl: In NH3 (ammonia), we have one nitrogen (N) atom combined with three hydrogen (H) atoms. In NH4Cl (ammonium chloride), we have one nitrogen (N) atom combined with four hydrogen (H) atoms. The ratio of N to H in NH3 is 1:3, while in NH4Cl, it is 1:4. Both ratios are small whole numbers, so this pair of compounds can illustrate the law of multiple proportions.
b) ZnO2 and ZnCl2: In ZnO2 (zinc dioxide), we have one zinc (Zn) atom combined with two oxygen (O) atoms. In ZnCl2 (zinc chloride), we have one zinc (Zn) atom combined with two chlorine (Cl) atoms. The ratio of Zn to O in ZnO2 is 1:2, and in ZnCl2, it is 1:2 as well. The ratio is the same, so this pair of compounds does not illustrate the law of multiple proportions.
c) H2O and HCl: In H2O (water), we have two hydrogen (H) atoms combined with one oxygen (O) atom. In HCl (hydrochloric acid), we have one hydrogen (H) atom combined with one chlorine (Cl) atom. The ratios of H to O in H2O and H to Cl in HCl are different; hence, this pair of compounds does not illustrate the law of multiple proportions.
d) NO and NO2: In NO (nitric oxide), we have one nitrogen (N) atom combined with one oxygen (O) atom. In NO2 (nitrogen dioxide), we have one nitrogen (N) atom combined with two oxygen (O) atoms. The ratio of N to O in NO is 1:1, while in NO2, it is 1:2. Both ratios are small whole numbers, so this pair of compounds can illustrate the law of multiple proportions.
Therefore, the pairs of compounds that can illustrate the law of multiple proportions are:
a) NH3 and NH4Cl
d) NO and NO2