Unit 1, Topic 5a - Acids and Alkalis Flashcards
When metals burn in air or oxygen what type of compound is made?
Metal Oxide
Be able to write balanced equations for metals burning in air.
Look at LIs + Booklet
What type of solution do metal oxides that dissolve in water tend to produce?
Alkali
Do all metal oxides dissolve in water?
No
Where can you fid out if metal oxides dissolve in water?
Page 8 of the data booklet.
Write the names of 2 metal oxides that dissolve in water?
Potassium oxide, Sodium Oxide
Write the names of 2 metal oxides that do not dissolve in water?
Aluminium oxide, Zinc oxide.
Give the names of the products for the 2 metal oxides that do dissolve.
Potassium oxide giving potassium hydroxide, Sodium oxide giving sodium hydroxide.
When non-metals burn in air or oxygen what type of compound is made?
Non-metal oxide
Be able to write balanced equations for non-metals elements burning in air.
Look at LIs + Booklet.
What type of solution do non-metal oxides that dissolve in water tend to produce?
Acid
What is required to enable nitrogen to react with oxygen?
High energy e.g spark, lightning
Name the oxide produced when nitrogen reacts with oxygen what oxide is produced?
Nitrogen dioxide.
Which acid is produced when Nitrogen Dioxide dissolves in water?
Nitric acid
What type of oxide would phosphorus produce?
Acidic
What type of oxide would hydrogen produce?
Neutral
What type of solution do metal hydroxides that dissolve in water produce?
Alkaline solutions
The pH scale is continuous from below _ to above _
1/14
What type of solution has a pH less than 7?
Acid or acidic
What type of solution has a pH more than 7?
Alkaline or Alkali
What pH do pure water and neutral solutions have?
7
Name 2 common acids in use home in the laboratory.
Home- Vinegar, lemon juice, soda water, fizzy drinks.
Lab- Hydrochloric, sulfuric, nitric
Name 2 common alkalis in. use at home and in the laboratory.
Home- Sodium Bicarbonate, toothpaste, dishwater tablets.
Lab- Sodium Hydroxide, calcium hydroxide, ammonia
What type of solution is formed when ammonia dissolves in water?
alkali
Do acids conduct electricity and why?
Yes, they are ionic and the ions are free to move.
What type of bonding do alkalis have?
ionic
Which gas is always produced at the negative electrode when acids are electrolysed?
Hydrogen
Which ion is present in all acid solutions?
H+
Which ion is present in all alkaline solutions?
OH-
In water and neutral solutions, how don the con concentrations of hydrogen ions and hydroxide ions compare?
equal
How do the concentrations of hydrogen ions and hydroxide ions compare in acidic soloution?
H+ > OH-
How do the concentrations of hydrogen ions and hydroxide ions compare in an alkaline solution?
OH- > H+
What happens to the concentration of hydrogen ions if an acid is diluted?
It decreases
What happens to the pH of hydrogen ions if an acid is diluted?
It decreases towards 7
How well does pure water conduct electricity?
Hardly conducts at all, water dissociates or cones very slightly into H+ and OH- ions and these ions are in equilibrium with H20 molecules. There are many more unionised H2) molecules compared with the two ions so there is some conductivity but very little because of the low concentration of H+ and OH- ions.
Write the equation for the water equilibrium?
H+(aq) + OH- = H20
Know how to write the ionic formulae for hydrochloric acid and sulfuric acid.
Practice this.
Be able to write the ionic formula for solid posttassium hydroxide and solid magnesium hydroxide.
Practice this.
What are the units of concentration?
mol l-1
Write the triangle relating number of moles volume and concentration.
mol
_______
l |concentration
Be able to calculate either the number of moles of a solute, the volume or concentration of a solution given the other two pieces of information.
Practice and look at notes.
Describe the difference between a concentrated solution and a dilute solution.
Concentrated-large quantity of dissolved solute, small quantity of water.
Dilute- Small quantity of dissolved solute, large quantity of water.
What happens to the pH of an acid with a pH of 3 when 1cm3 is diluted to 10cm3 with water?
Increases pH from 3 to 4.
How does concentration affect the conductivity of an ionic solution?
The higher the concentration the higher the conductivity.
How does a ten-fold dilution of an alkali affect its pH?
lowers the pH by 1
What is the name given to a solution which has an accurately known concentration?
Standard
