Question

acetaldehyde is a substance commonly used in chemical factories. it is often produced by combining ethylene gas and oxygen gas.
consider the following reaction:
4 molecules of ethylene (c₂h₄) react with 2 molecules of oxygen (o₂) to produce some amount of acetaldehyde (c₂h₄o).
complete the table below.
during this reaction, how many molecules of acetaldehyde (c₂h₄o) are produced?

Explanation:

Step1: Count hydrogen atoms

Each \(C_2H_4\) has 4 H atoms. There are 4 \(C_2H_4\) molecules. So hydrogen atoms from ethylene: \(4\times4 = 16\).

Step2: Count carbon atoms

Each \(C_2H_4\) has 2 C atoms. There are 4 \(C_2H_4\) molecules. So carbon atoms: \(4\times2=8\).

Step3: Count oxygen atoms

Each \(O_2\) has 2 O atoms. There are 2 \(O_2\) molecules. So oxygen atoms: \(2\times2 = 4\).

Step4: Determine acetaldehyde molecules

Let the number of \(C_2H_4O\) molecules be \(x\).
For C: \(2x=8\) (from carbon balance), so \(x = 4\).
Check H: Each \(C_2H_4O\) has 4 H. For \(x = 4\), H atoms \(=4\times4=16\) (matches).
Check O: Each \(C_2H_4O\) has 1 O. For \(x = 4\), O atoms \(=4\times1 = 4\) (matches).

Answer:

Chemical element	Number of atoms in the reaction
C	\(8\)
O	\(4\)

Number of acetaldehyde (\(C_2H_4O\)) molecules produced: \(4\)