Multiple Choice
Given that the empirical formula of a compound is C_3H_5 and its molecular mass is 205.4 g/mol, what is the value of n in the relationship: molecular formula = (empirical formula)_n?
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3. Chemical Reactions
Empirical Formula
Multiple Choice
Which of the following is the empirical formula for a compound that is 36.86% nitrogen (N) and 63.14% oxygen (O) by mass?
A
NO
B
N2O3
C
N2O
D
NO2
Verified step by step guidance1
Step 1: Assume a 100 g sample of the compound so that the mass percentages can be directly converted to grams: 36.86 g of nitrogen (N) and 63.14 g of oxygen (O).
Step 2: Convert the masses of each element to moles by dividing by their respective atomic masses: use 14.01 g/mol for nitrogen and 16.00 g/mol for oxygen. Calculate moles of N as \(\frac{36.86}{14.01}\) and moles of O as \(\frac{63.14}{16.00}\).
Step 3: Determine the simplest whole number mole ratio by dividing both mole values by the smaller number of moles obtained in Step 2.
Step 4: If the mole ratio is not close to whole numbers, multiply both ratios by the smallest integer that converts them to whole numbers (e.g., 2, 3, 4, etc.).
Step 5: Write the empirical formula using the whole number mole ratios as subscripts for nitrogen and oxygen atoms, respectively.
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