Question | Answer |
how is a detergent made? | neutralising an organic acid with an alkali |
remember the equation for neutralisation? | acid + alkali - salt + waterq |
what part of the neutralisation equation is the detergent? | salt |
what does perfume do in washing powder? | makes clothes smell nice |
what does the detergent do in washing powder? | lifts dirt of clothes |
what do the enzymes do in washing powder? | remove food stains, but only work at low temperatures |
what do water softeners do in washing powder? | softens hard water |
what does the optical brightener do is washing powder? | sticks to clothes and makes them really white |
what does bleach do in washing powder? | removes coloured stains |
advantages of washing clothes at low temperatures? | -good for the environment
-less energy needed
-less greenhouse gases
-reduced chance of colours running |
what does hydrophilic mean? | doesn't like water. this end sticks to the grease |
what does hydrophobic mean? | likes water. this end joins to the water and pulls the grease off the fabric/dish |
why is dry-cleaning used? | some clothes are damaged if washed in water |
what is used instead of water in dry-cleaning? | organic solvent |
why does dry-cleaning remove grease stains better than water? | grease stains don't dissolve in water but they do in the dry-cleaning solvent |
what makes dry-cleaning better at removing grease stains than water? | dry-cleaning solvent and grease have weak intermolecular forces, meaning they join easily. |
what makes water not as good at removing grease stains than dry-cleaning? | water have stronger intermolecular forces, called hydrogen bonds. this means that they can't stick to the grease as they are stuck to each other too strongly. |