Dishwasher tablets contain chemicals which remove dirt from dishes - Scottish Highers Chemistry - Question 9 - 2017

Another action of the bleach produced by the dishwasher tablets is to break down colored compounds, effectively removing stains and making dishes cleaner.

First, calculate the number of moles of hydrogen peroxide.

Moles of H₂O₂ = ( \frac{0.051 g}{34 g/mol} \approx 0.0015 mol )

From the decomposition reaction, 2 moles of H₂O₂ produce 1 mole of O₂.

Thus, the moles of O₂ produced = ( 0.0015 mol H₂O₂ \times \frac{1 mol O₂}{2 mol H₂O₂} \approx 0.00075 mol O₂ )

Now, using the molar volume of gas at standard conditions (24 L/mol):

Volume of O₂ = ( 0.00075 mol \times 24 L/mol \approx 0.018 L )

The small, water-soluble molecules made when proteins are broken down completely are called amino acids.

The functional group circled in the protein structure is the -SH group, known as a thiol group.

One possible structural formula of an amino acid resulting from the breakdown could be:

       NH2
        |
  HOOC-C-CH2-CH3
        |
       SH

This represents a typical amino acid structure, including the amino and carboxyl groups.

The term used to describe the change in shape of enzyme molecules is denaturation.

A change in conditions that could cause enzyme molecules to change shape is an increase in temperature above the enzyme's optimal range or a change in pH, making it too acidic or too alkaline.

The type of reaction shown in the first stage for producing TAED is known as a condensation reaction.

The structural formula for TAED is:

H3C   O   O   C   CH3
    \ /    \/ 
     N—C—C—N
    /      \ 
   CH3   CH3