Chemistry EoY- Neutralisation of Acids

What colour does red and blue litmus paper turn in a base?

Red turns blue, blue turns red

What colour does red and blue litmus paper turn in an acid?

Red stays the same, blue turns red

What colour does red and blue litmus paper turn in neutral?

Stays the same.

What is neutralisation?

An acid and alkali reacts together, forms water and a salt only

An alkali is a s______ b____?

An alkali is a soluble base

Bases are u_____ s______?

Bases are usually solid

All alkalis are bases but not all bases are alkalis.

All alkalis are bases but not all bases are alkalis.

What is a base?

A substance that neutralises an acid

Why does sulfate and nitrate end with "ate"?

They contain oxygen

What do all acids contain?

Hydrogen

Alkalis have what in them?

Hydroxide

How do you name a salt?

First part comes from the metal in the alkali/base used, the second part comes from the acid used.

What is a BAWS reaction?

Base + acid --> Water + Salt (neutralisation), oxide means base

What is an AAWS reaction?

Alkali + acid --> Water + Salt (neutralisation), hydroxide means alkali

What is a CAWS COD reaction?

Carbonate + acid --> water + salt + carbon dioxide (gas bubbles produced)

How to make copper (II) sulfate crystals?

Pour 40cm3 of sulfuric acid into a beaker, heat gently to speed up the reaction. Use spatula add an excess of copper oxide (base), so neutralisation occurs. Add + stir with a glass rod, colour changes to blue, and stop stirring when there is undissolved copper oxide. Filter with filter paper, funnel, a pure blue solution. Pour solution into evaporating dish. Heat until a white ring forms. Leave to cool, filter with distilled water.

What is the test for a carbonate salt?

Put a solid sample into a test tube, and put 2-3 cm3 of limewater into another. Add dilute HCI to the solid salt and quickly attach the bung with the delivery tube. If the salt contains a carbonate then the limewater will go milky.

What is the chemical test for a chloride salt?

Add 1 spatula of the salt into a test tube, and dissolve in distilled water. Add 6 drops of nitric acid and then 1cm3 of silver nitrate solution. If there is a white precipitate, then the salt is a chloride.

What is the flame test for the metal present in salts?

Use a piece of nichrome wire, and dip it into HCI to clean out impurities. Put into blue flame of Bunsen and repeat until there is no discolouration of flame. Dip back into acid, then into solid salt, and then back into flame. Notice the colour of flame.

What is the flame colour of Sodium?

Bright yellow/ orange

What is the flame colour of Potassium?

Lilac Flame

What is the flame colour of Calcium?

Red

What is the flame colour of Copper?

Green

What is the burette titration practical?

Fill a burette with Orange Juice A solution. Let some run out so the burette nozzle is full. Measure 25cm3 of sodium hydroxide, with measuring cylinder and pour into conical flask. Add 6 drops of litmus. Put the flask on a white tile, and let the solution run until the litmus changes colour. Record the volume of juice needed. Repeat

What is a white precipitate?

Insoluble solid, like a suspension

Why is nitric acid used?

Removes impurities

Difference between alkali and base:

An alkali is a metal hydroxide, but a base is a metal oxide. A base is insoluble in water, but alkalis are soluble in water.

What is the common salt practical?

Meausre 20cm3 of sodium hydroxide using a 25cm3 measuring cylinder into a conical flask. Add 4 drops of phenolphthalein indicator. Fill the burette with HCI acid and run out through the tap. Check base of meniscus is on the 0cm3 mark. Place the flask beneath the burette on a white tile, and add acid into the flask. Swirl flask and stop when there is a colour change.

What colour change is there in the common salt practical?

Pink to colourless