Chemistry - Unknown Topics Flashcards
(28 cards)
What’s an acid?
A substance that dissolves in water to make a solution with less than 7
Concentrated acids have more //// than water
Dilute acids have more ///// than ///_/
- Acid
- Water
- Acid
What’s an alkali?
A base that dissolves in water to give a solution with pH more than 7
What is an indicator?
A substance that changes colour in acidic and alkaline solutions
How can indicators be made naturally?
From red cabbage or other coloured plant substances
What is the pH scale?
A scale from 0-14 that shows how acidic or alkaline something is
What is neutral on the pH scale?
7
pH of less than 7 is:
Acidic
A pH of more than 7:
Alkaline
What is Universal Indicator?
A mixture of indicators that shows the pH scale
A / ////_/ is more accurate to measure pH scale
pH meter
What is a base?
An insoluble metal oxide or hydroxide
What happens when a base (such as an alkaline) reacts with an acid?
Neutralisation
How can a neutralisation reaction be followed?
Using an indicator
What is one example of something made during neutralisation?
Salt
What is the word equation for neutralisation?
Acid + Base = Salt + Water
What are some everyday uses of neutralisation?
- Treating indigestion
- Bee and wasp stings
- soil treatment
What is an element?
A substance made of one type of atom
Are there more metals or non-metals in the periodic table?
More metals
What are physical properties of metals?
- Shiny
- Good Conductors
- Malleable
- Ductile
How do you test the physical properties of an element to see if it’s a metal?
You could gently heat it and if it doesn’t melt its probably a metal, or something similar
What is an allotropy?
An element having different forms, such as carbon - graphite and diamond
What are allotropes of carbon and tin?
Carbon: diamond & Graphite
Tin: White & grey
What is a compound?
Two or more elements chemically combined in fixed proportions
