Question

Determine the molecular formulas to which the following empirical formulas and molar masses pertain.a. SNH (188.35 g/mol)b. NPCl2 (347.64 g/mol)c. CoC4O4 (341.94 g/mol)d. SN (184.32 g/mol)

Answer 1

To determine the molecular formulas, we need to calculate the ratio of empirical formula units to molecular formula units by dividing the molar mass by the empirical formula mass. The molecular formulas for the given compounds are (SNH)4, (NPCl2)3, (CoC4O4)2, and (SN)5.

Step-by-step explanation:

To determine the molecular formulas for the given empirical formulas and molar masses, we need to know the molar mass of each element present in the compound. By comparing the molar mass of the compound with the empirical formula mass, we can determine the ratio of empirical formula units to molecular formula units. Let's calculate the molecular formulas for each given compound:

a. SNH (188.35 g/mol): The empirical formula mass is 45.11 g/mol, and the molar mass is 188.35 g/mol. Dividing the molar mass by the empirical formula mass gives us the ratio of empirical formula units to molecular formula units: 188.35 g/mol / 45.11 g/mol = 4.18. Therefore, the molecular formula is (SNH)4.

b. NPCl2 (347.64 g/mol): The empirical formula mass is 102.01 g/mol, and the molar mass is 347.64 g/mol. Dividing the molar mass by the empirical formula mass gives us the ratio of empirical formula units to molecular formula units: 347.64 g/mol / 102.01 g/mol = 3.41. Therefore, the molecular formula is (NPCl2)3.

c. CoC4O4 (341.94 g/mol): The empirical formula mass is 159.91 g/mol, and the molar mass is 341.94 g/mol. Dividing the molar mass by the empirical formula mass gives us the ratio of empirical formula units to molecular formula units: 341.94 g/mol / 159.91 g/mol = 2.14. Therefore, the molecular formula is (CoC4O4)2.

d. SN (184.32 g/mol): The empirical formula mass is 32.06 g/mol, and the molar mass is 184.32 g/mol. Dividing the molar mass by the empirical formula mass gives us the ratio of empirical formula units to molecular formula units: 184.32 g/mol / 32.06 g/mol = 5.75. Therefore, the molecular formula is (SN)5.

Answer 2

`\begin{gathered} a)S_4N_4H_4 \\ b)N_3P_3Cl_6 \\ c)Co_2C_8O_8 \\ d_{})S_4N_4 \end{gathered}`

Explanations:

The molecular formula is defined as the formula that gives the total atoms in each molecule of a substance. It is expressed generally as:

`\text{ (empirical formula)}_n=molar\text{ mass}`

We are to get the molecular formulas to which the following empirical formulas and molar masses pertain.

a) For the empirical formula SNH with the molecular formula (188.35 g/mol)

`\begin{gathered} (SNH)_n=188.35 \\ (32+14+1)_n=188.35 \\ 47n=188.35 \\ n=(188.35)/(47) \\ n\approx4.00 \end{gathered}`

Get the molecular formula for SNH

`(SNH)_4=S_4N_4H_4`

b) For the empirical formula NPCl2 with a molar mass of 347.64g/mol

`\begin{gathered} (NPCl_2)_n=347.64 \\ (14+31+2(35))_n=347.64 \\ 115n=347.64 \\ n=(347.64)/(115) \\ n\approx3.00 \end{gathered}`

Get the molecular formula of NPCl2

`(NPCl_2)_3=N_3P_3Cl_6`

c) For the empirical formula CoC4O4 with a molar mass of 341.94g/mol

`\begin{gathered} (CoC_4O_4)_n=341.94 \\ (60+4(12)+4(16))_n=341.94 \\ (60+48+64)_n=341.94 \\ 172n=341.94 \\ n=(341.94)/(172) \\ n\approx2.0 \end{gathered}`

Get the molecular formula of CoC4O4

`(\text{CoC}_4O_4)_2=Co_2C_8O_8`

d) For the empirical formula SN with a molar mass of 184.32/mol

`\begin{gathered} (SN)_n=184.32 \\ (32+14)_n=184.32 \\ 46n=184.32 \\ n=(184.32)/(46) \\ n\approx4.00 \end{gathered}`

Get the molecular formula of SN

`\begin{gathered} (SN)_4=S_4N_4 \\ \end{gathered}`