What do acids release when dissolved in water

H⁺ ions

What is a strong acid, with an example

an acid that releases all its hydrogen atoms into the solution as H⁺ ions and completely dissociates in in aqueous solution e.g. HCl

What is a weak acid with an example

an acid that only releases a small proportion of its available hydrogen atoms into a solution as H⁺ ions, this type of acid partially dissociates in aqueous solution e.g. CH₃COOH_(aq) ⇌ H⁺+ CH₃COO^-, even then only one in every hundred molecules dissociate, making this a weak acid

what is a base

something that neutralises an acid to form a salt

what is an alkali

a base that dissolves in water to release OH^- ions into the solution

what is the ionic equation for a neutralisation reaction (for hydroxides and carbonates)

H⁺ + OH^- → H₂O

CO₃ ^2- + 2H⁺ _→ H₂O + CO₂

What is and what are the uses of a titration

a technique used to accurately measure the volume of one solution that reacts exactly with another solution, they can be used for:

• finding an unknown concentration
• identification of unknown chemicals
• finding the purity of a substance

Which container is used to prepare a standard solution

volumetric flask

explain the steps in preparing a standard solution

1. accurately weigh the solid
2. dissolve the solid in less water than is needed in a beaker (use distilled water for all future steps)
3. rinse the weighing boat, putting the water in the beaker
4. transfer the water from the beaker to the volumetric flask
5. empty the beaker, transferring the contents into the volumetric flask
6. rinse the beaker, emptying it into the volumetric flask
7. fill the volumetric flask up to the neck with more water
8. using a pipette and ensuring you are at eye level with the line on the flask, use water to fill the flask up to the line, ensuring the bottom of the meniscus is touching the line
9. insert a bung and invert the volumetric flask three times to ensure the dissolved solid is evenly distributed

how do you calculate the mean titre in a titration

only using the concordant (within 0.1 cm^3 of each other) results

what is the equation used in titrations involving conc.

no. of moles (mol) = concentration (mol dm^-3) * volume (dm³) or n = cv