calculate the number of molecules of hydrogen and carbon present in 4 gof methane.
To calculate the number of molecules of hydrogen and carbon present in 4 grams (4 g) of methane (CH4), you need to use the concept of molar mass and Avogadro's number.
Step 1: Find the molar mass of methane (CH4).
The molar mass of carbon (C) is approximately 12.01 g/mol, and the molar mass of hydrogen (H) is approximately 1.01 g/mol. Since methane contains one carbon and four hydrogen atoms, its molar mass is:
(1 mol C × 12.01 g C/mol) + (4 mol H × 1.01 g H/mol) = 16.05 g/mol
Step 2: Calculate the number of moles of methane.
To determine the number of moles, divide the given mass (4 g) by the molar mass of methane:
4 g CH4 ÷ 16.05 g/mol ≈ 0.249 mol CH4
Step 3: Calculate the number of molecules.
Avogadro's number states that one mole of a substance contains 6.022 × 10^23 molecules. Multiply the number of moles by Avogadro's number to find the number of molecules:
0.249 mol CH4 × 6.022 × 10^23 molecules/mol ≈ 1.50 × 10^23 molecules of CH4
Since each molecule of methane contains one carbon atom and four hydrogen atoms, the number of carbon atoms (C) and hydrogen atoms (H) can be calculated accordingly:
Number of carbon (C) atoms = 0.249 mol CH4 × 6.022 × 10^23 molecules/mol = 1.50 × 10^23 atoms
Number of hydrogen (H) atoms = 0.249 mol CH4 × 6.022 × 10^23 molecules/mol × 4 atoms H/molecule CH4 = 6.01 × 10^23 atoms
Keep in mind that these numbers are approximate due to the molar masses used and rounding during calculations.