Neutralisation Reactions (T4) Flashcards Preview

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Flashcards in Neutralisation Reactions (T4) Deck (8)
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1
Q

What happens when an acid reacts with a metal hydroxide? Give the word equation and what you would observe in the reaction.

A

When an acid reacts with a metal hydroxide, the only products formed are salt plus water.

acid + metal hydroxide > a salt + water

You would observe:

  • a temperature rise
  • the pH of the reaction mixture changing
2
Q

What happens when a metal oxide reacts with an acid? Give the word equation and what you would observe.

A

When an acid reacts with a metal oxide, the only products formed are salt plus water.

acid + metal oxide > a salt + water

You would observe:

  • a temperature rise
  • the pH of the reaction mixture changing
3
Q

What happens when an acid reacts with a metal carbonate? Give the word equation and observations.

A

When an acid reacts with a metal carbonate, the products formed are a salt plus water and also carbon dioxide is formed.

acid + metal carbonate > a salt + water + carbon dioxide

You usually observe bubble of gas being given off during the reaction. You can show that the gas is carbon dioxide by bubbling it through limewater - it turns cloudy when it reacts with carbon dioxide.

4
Q

What is a neutralisation?

A
  • the chemical reaction that occurs when you mix together an acid and a base
  • a neutral solution is made when you mix just the right amount of acid and base together
5
Q

Give three examples for the use of neutralisation..

A
  • farmers use lime (calcium oxide) to neutralise acid soils
  • your stomachs contains hydrochloric acid and too much causes indigestion. Antacid tablets contains bases like magnesium hydroxide and magnesium carbonate to neutralise the extra acid
  • bee stings are acidic. They can be neutralised using baking powder which contains sodium hydrogen carbonate
6
Q

The reaction of acid and alkali can sometimes be so sensitive that mildly acidic reactions, like the binding of carbon dioxide into water, can cause changes in a mild alkali.

Using the change of calcium hydroxide in water as an example, explain what happens and give the word and chemical equations…

A

Calcium hydroxide + carbon dioxide > calcium carbonate + water

Ca(OH)2 + CO2 > CaCo3 + H2O

  • the reaction is visible from the water going cloudy
  • the salt formed takes the carbon from the gas and produces water, while forming a salt from the hydroxide
  • carbon dioxide gas dissolves to form carbonic acid
  • calcium carbonate precipitates out
  • calcium carbonate reacts with carbonic acid to form calcium hydrogencarbonate, which is more soluble, so the precipitate dissolves
7
Q

What are the word and chemical equations for the neutralisation of hydrogen and hydroxide?

A

Hydrogen (aq) + hydroxide (aq) > water (l)

H+(aq) + OH-(aq) > H2O(l)

8
Q

Neutralisation can be used to make..

A

Salts