Why we need Chemicals Flashcards
What is the formula for: Hydrochloric acid, Nitric acid, Sulfuric acid, Calcium carbonate, Magnesium hydroxide, Potassium sulphate?
HCl, HNO3 H2SO4 CaCO3 MgOH K2SO4
What are examples pure acidic compounds that are:
Solids,
Liquids,
Gases?
Solids: citric and tartaric acid
Liquids : sulfuric and ethanoic acids
Gases: hydrogen chloride
What are common alkalis?
Hydroxides of sodium, potassium and calcium
Using universal indicator what colours are acids and alkalis and what would they would be ranked on the pH scale?
From 1-6 and red to orange are acids
From 8-14 and blue to purple are alkalis
Neutral is 7 and green
What are the products of acids reacting with metals and their oxides, hydroxides and carbonates?
Acid + metal = salt + hydrogen
Acid + metal hydroxide/oxide = salt + water
Acid + metal carbonates = salt + water + carbon dioxide
What is a neutralisation reaction?
The reaction of an acid with an alkali to form a salt
What do acidic compounds produce when dissolved in water?
They produce aqueous hydrogen ions, H+ (aq)
What do alkaline compounds produce when dissolved in water?
They produce aqueous hydroxides ions, OH- (aq)
What do the hydrogen ions from the acid and hydroxide ions from the alkali react to produce?
H+ + OH- = ?
They react to form water
H+ + OH- = H2O
What does exothermic and endothermic reaction mean?
In an exothermic reaction energy is given out to the surrounding,
In an endothermic reaction energy is taken in from the surroundings
In an endothermic and exothermic reaction what happens to the energy levels of the reactants to the products?
In an exothermic reaction the reactants have more energy than the products,
In an endothermic reaction the reactants have less energy than the products
What do we use chemical synthesis for?
For food additives, fertilisers, dyestuffs, paints, pigments, pharmaceuticals
