Determine the molecular formula for each compound.
a) 94.1% oxygen and 5.9% hydrogen; molar mass = 34g
b) 50.7% carbon, 4.2% hydrogen, and 45.1% oxygen; molar mass = 142g

(would greatly appreciated if someone could explain the process, also use the correct amount of significant digits)

The molecular formula for compound (a) is H₂O₂

The molecular formula for compound (a) is C₆H₆O₄

A compound's molar mass determines what is the mass of one mole of that substance. One mole of a compound contains Avogadro's number of molecules = molecules.

The percent composition of elements in 1 mole of compound can be used to get the exact number of moles of each element present in per mole of compound.

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a) 94.1% Oxygen and 5.9% Hydrogen; molar mass = 34 g

The given compound's percent composition is as follows :

For O :

94.1% of oxygen refers to 94.1 g of Oxygen per 100 g of compound.

Mass of Oxygen in 34 g of compound =

To determine the number of moles of element O present in one mole of compound :

Molar mass of Oxygen = 15.9994 g/mol

The mass in grams of one mole of substance is called molar mass.

One mole of oxygen has 15.9994 grams of O.

Number of moles of O in 31.994 g of O =

In whole numbers,

Number of moles of O in 31.994 g of compound = 1.9996 ≈ 2

Similarly,

For H :

5.9% of hydrogen refers to 5.9 g of Hydrogen per 100 g of compound.

Mass of Hydrogen in 34 g of compound =

To determine the number of moles of element H present in one mole of compound :

Molar mass of Hydrogen = 1.00794 g/mol

The mass in grams of one mole of substance is called molar mass.

One mole of hydrogen has 1.00794 grams of H.

Number of moles of H in 2.006 g of H =

In whole numbers,

Number of moles of H in 2.006 g of compound = 1.9901 ≈ 2

The molecular formula for this compound (a) can be written as

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b) 50.7% Carbon, 4.2% Hydrogen, and 45.1% Oxygen; molar mass = 142 g

The given compound's percent composition is as follows :

For C :

50.7% of carbon refers to 50.7 g of carbon per 100 g of compound.

Mass of Carbon in 142 g of compound =

To determine the number of moles of element C present in one mole of compound :

Molar mass of Carbon = 12.011 g/mol

The mass in grams of one mole of substance is called molar mass.

One mole of carbon has 12.011 grams of C.

Number of moles of C in 71.994 g of C =

In whole numbers,

Number of moles of C in 71.994 g of compound = 5.9940 ≈ 6

For H :

4.2% of hydrogen refers to 4.2 g of Hydrogen per 100 g of compound.

Mass of Hydrogen in 142 g of compound =

To determine the number of moles of element H present in one mole of compound :

Molar mass of Hydrogen = 1.00794 g/mol

The mass in grams of one mole of substance is called molar mass.

One mole of hydrogen has 1.00794 grams of H.

Number of moles of H in 5.964 g of H =

In whole numbers,

Number of moles of H in 2.006 g of compound = 5.9170 ≈ 6

For O :

45.1% of oxygen refers to 45.1 g of Oxygen per 100 g of compound.

Mass of Oxygen in 142 g of compound =

To determine the number of moles of element O present in one mole of compound :

Molar mass of Oxygen = 15.9994 g/mol

The mass in grams of one mole of substance is called molar mass.

One mole of oxygen has 15.9994 grams of O.

Number of moles of O in 64.042 g of O =

In whole numbers,

Number of moles of O in 31.994 g of compound = 4.002 ≈ 4

The molecular formula for this compound (b) can be written as