Year 10, writing fully balanced chemical equations homework

Year 10, writing fully balanced chemical equations homework

A whole lot of the chemistry you have studied this year comes together in this exercise.

  • ions and how they are formed.
  • naming ionic compounds and writing their formula
  • word equations.

…….. and finally the last piece in the jigsaw writing a fully balanced chemical equation.

If you study NCEA chemistry at level 1 next year a rough guide is

Achievement: writing word equations.

Merit: Inserting chemical formulae into an equation.

Excellence: producing a fully balanced chemical equation.

Revise what we did today by watching the video then do the short exercise. In your notebook write down the word equation and complete it (achievement) Underneath the word equation insert the chemical formula of each substance (merit). Finally balance the equation (excellence) NOTE this usually involves sticking 2 in front of something

1 sodium hydroxide      +   sulphuric acid             ——->

2 copper oxide                 +  hydrochloric acid     ——–>

 

Waimangu Valley and Mount Tarawera

Waimangu Valley and Mount Tarawera today.

The Okataiana Volcanic centre lies in the Taupo volcanic zone and there have been several huge explosions in the last 250,000 years. After each eruption the area surrounding the vent collapsed filling the space left by the escaped magma. A large caldera roughly 18km by 25km has formed and less violent eruptions over the last 40,000 years have filled its floor with a mixture of pumice. lava flows and lava domes.

Tarawera volcano had four major eruptions between 18,000 and 800 years ago. The 1886 eruption which formed the Waimangu valley was by comparison a small event but is still the largest in European times. A rift 18 km long opened up in the space of a few hours. Huge volumes of molten basaltic magma and mud resulting from the explosion of the hydrothernal system under Lake Rotomahana were ejected. The eruption destroyed the famous pink and white terraces. Seven small villages in the vicinity of the lake were destroyed with the loss of 120 lives.

Feaures of the valley and the eruption of Mount Tarawere that brought it into existence

Untitled from john west on Vimeo.

Sources:
Waimangu Volcanic Valley leaflets, author Prof RF Keam, Physics Department, University of Auckland.

Neutralising acids with bases to form salts

Neutralising acids with bases to form salts

Acids and water

  Acids react with water molecules to form hydrogen ions . Acidic solutions have an excess of hydrogen ions over hydroxide ions. The acids we commonly use in the laboratory are:

  • Hydrochloric, HCl
  • Sulphuric, H2SO4
  • Nitric, HNO3

.pH

  •  Neutralising acids with bases.

  • The acidity of an acid can be neutralised by removing the excess of hydrogen ions

Substances that remove hydrogen ions and neutralise acids are called bases.

Chemically all metal oxides and hydroxides are bases.

Bases that are soluble in water have a special name. They are called alkalis e.g. Sodium hydroxide and potassium hydroxide

 

 

 

Making a salt in the Laboratory.

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