Question

The pain reliever morphine contains 17.900 g C, 1.680 g H, 4.225 g O, and 1.228 g N. Determine the empirical Formula.

Answer 1

Answer: The empirical formula is $C_{17}H_{19}O_3N$

Explanation:

Mass of C= 17.900 g

Mass of H = 1.680 g

Mass of O = 4.225 g

Mass of N = 1.228 g

Step 1 : convert given masses into moles.

Moles of C =$\frac{\text{ given mass of C}}{\text{ molar mass of C}}= \frac{17.990g}{12g/mole}=1.5moles$

Moles of H =$\frac{\text{ given mass of H}}{\text{ molar mass of H}}= \frac{1.680g}{1g/mole}=1.680moles$

Moles of O =$\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{4.225g}{16g/mole}=0.264moles$

Moles of N =$\frac{\text{ given mass of N}}{\text{ molar mass of N}}= \frac{1.228g}{14g/mole}=0.087moles$

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For C = $\frac{1.5}{0.087}=17$

For H = $\frac{1.680}{0.087}=19$

For O =$\frac{0.264}{0.087}=3$

For N = $\frac{0.087}{0.087}=1$

The ratio of C : H: O: N = 17: 19: 3: 1

Hence the empirical formula is $C_{17}H_{19}O_3N$