Chemical Reactions Flashcards
What are Acids?
- All contain at least one hydrogen ion
- Have a sour taste
- Conduct electricity when mixed with water
- Can neutralise bases
- React with many metals
- Have a pH less than 7
What are some examples of acids?
- Common examples include: Oranges, lemons, grapes, apples Vitamin C and yoghurt
- Chemical examples include: Hydrochloric acid HCl, Nitric acid HNO3 and Sulfuric acid H2SO4
What are the two types of acids?
Weak Acids + Strong Acids
What are weak acids?
- Give away Hydrogen ions, but not easily
- Much safer than strong acids
- We eat and drink many weak acids
- Weak acids are used as preservatives in food
What are strong acids?
- Readily give away their Hydrogen ions
- They are corrosive i.e. will burn through objects
What are Bases?
- Are the chemical opposite of an acid
- They neutralise acids
- Bases that dissolve in water are called alkalis
- Have a bitter taste
- Have a soapy/slippery feel to them
- Have a pH greater than 7
What is another name for a base?
Alkaline
What are some examples of bases?
- Common examples include: many household cleaners
- Chemical examples include: Sodium Hydroxide NaOH, Potassium HydroxideKOH and Barium Hydroxide Ba(OH)2
What are the two types of bases?
Weak bases + Strong bases
What are weak bases?
- Will accept a hydrogen ion, but not easily
- Generally the bases found in household cleaning products because they are safer than strong bases
What are strong bases?
- Accept hydrogen ions and will take them from other places
- Attack living tissues and cause serious burns
- Are caustic and very harmful
What is a Dilute solution?
A dilute solution is one that has very few solute particles in a relatively large volume of solvent
What is a Concentrated solution?
A concentrated solution has more solute particles dissolve in the solvent. Concentrated acids and bases are very dense.
What is an Indicator?
An indicator changes colour in the presence of an acid or base. They tell us whether a solution is acidic or basic.
What are some examples of indicators?
- Litmus paper – only gives acid or base indication,
- Universal indicator– indicates strength of the acid or base
- Red cabbage indicator – indicates strength of the acid or base
What is the pH scale?
Measures how strong an acid or a base solution is;
- Ranges from 1 - 14
- Below 7 = acidic (the lower the pH the stronger the acid)
- 7 = neutral
- Above 7 = basic/alkaline (the higher the pH the stronger the base)
What are the possible reactions of acid?
- Acid + base → salt + water
- Acid + metal carbonate → salt + water (H2O) + carbon dioxide (CO2)
- Acid + metal → salt + Hydrogen (H2)