Question

do now: copy and complete in your notebook
the sugar used in coffee is called sucrose. it has the chemical formula:
c₁₂h₂₂o₁₁

a) how many elements are in sucrose? ______.
name them____________________.
how many atoms are in a sucrose molecule?______
explain:____________________

Explanation:

Part 1: Number of elements in sucrose

To determine the number of elements, we identify the different chemical symbols in the formula \( \ce{C_{12}H_{22}O_{11}} \). The symbols are \( \ce{C} \) (Carbon), \( \ce{H} \) (Hydrogen), and \( \ce{O} \) (Oxygen). Counting these unique symbols gives the number of elements.

Part 2: Naming the elements

From the chemical symbols in the formula, the elements are Carbon (from \( \ce{C} \)), Hydrogen (from \( \ce{H} \)), and Oxygen (from \( \ce{O} \)).

Part 3: Number of atoms in a sucrose molecule

To find the total number of atoms, we sum the number of each type of atom. For Carbon: \( 12 \) atoms (from \( \ce{C_{12}} \)), Hydrogen: \( 22 \) atoms (from \( \ce{H_{22}} \)), and Oxygen: \( 11 \) atoms (from \( \ce{O_{11}} \)). We calculate the total as \( 12 + 22 + 11 \).

Step 1: Identify elements from the formula

The chemical formula of sucrose is \( \ce{C_{12}H_{22}O_{11}} \). The symbols \( \ce{C} \), \( \ce{H} \), and \( \ce{O} \) represent different elements.
Count of elements: \( 3 \).

Step 2: Name the elements

From the symbols: \( \ce{C} \) = Carbon, \( \ce{H} \) = Hydrogen, \( \ce{O} \) = Oxygen.

Step 3: Calculate total number of atoms

Sum the subscripts (number of each atom):
Carbon atoms: \( 12 \), Hydrogen atoms: \( 22 \), Oxygen atoms: \( 11 \).
Total atoms: \( 12 + 22 + 11 = 45 \).

Step 4: Explain the atom count

The subscript in a chemical formula indicates the number of atoms of that element in one molecule. Adding the subscripts for each element (12 for C, 22 for H, 11 for O) gives the total number of atoms in one sucrose molecule.

Answer:

• Number of elements in sucrose: \( \boldsymbol{3} \)
• Name of elements: Carbon, Hydrogen, Oxygen
• Number of atoms in a sucrose molecule: \( \boldsymbol{45} \)
• Explanation: Add the subscripts of each element in the formula \( \ce{C_{12}H_{22}O_{11}} \): \( 12 + 22 + 11 = 45 \).