If I have a 1200 gram sample of a soft drink and it contains 180 grams of sugar, the percentage by mass of the sugar in the drink is 15%. If the sugar in the drink is sucrose (C12H22O11), how many grams of pure carbon can be obtained from decomposing all of the sugar in the soft drink?

76 grams

Find the formula mass of sucrose=342 grams
Part/whole*100 which is 144/342*100=42.1%
42.1% of 180 grams= 76 grams

To determine the number of grams of pure carbon that can be obtained from decomposing all of the sugar in the soft drink, we need to calculate the molar mass of sucrose (C12H22O11) and determine the mass percent of carbon in its chemical formula.

Step 1: Calculate the molar mass of sucrose (C12H22O11).
The molar mass of carbon (C) is approximately 12.01 g/mol.
The molar mass of hydrogen (H) is approximately 1.01 g/mol.
The molar mass of oxygen (O) is approximately 16.00 g/mol.

For sucrose:
(12.01 g/mol × 12 C atoms) + (1.01 g/mol × 22 H atoms) + (16.00 g/mol × 11 O atoms) = 342.30 g/mol

Step 2: Determine the mass percent of carbon in sucrose.
The molecular formula of sucrose (C12H22O11) suggests that there are 12 carbon atoms out of a total of 12 + 22 + 11 = 45 atoms in the compound.

Mass percent of carbon = ((12.01 g/mol × 12 C atoms) / 342.30 g/mol) × 100%
= 42.11%

Step 3: Calculate the grams of pure carbon obtained from the sugar in the soft drink.
Since the soft drink contains 180 grams of sugar, we can use the mass percent of carbon to determine the grams of pure carbon.

Grams of pure carbon = (Mass percent of carbon / 100%) × Mass of sugar
= (42.11% / 100%) × 180 g
= 75.80 g

Therefore, decomposing all of the sugar in the soft drink will yield approximately 75.80 grams of pure carbon.