SKILLS TASK How to balance symbol equations Magnesium
➜ SKILLS TASK How to balance symbol equations ➜ Magnesium burns in air to form magnesium oxide ➜ The equation for this reaction is magnesium + oxygen → magnesium oxide ➜ The mass of the product (magnesium oxide) is greater than the mass of the metal because oxygen from the air is added to the magnesium to form a solid compound. ➜ We can show the number and types of atoms in the reactants and products. Chemistry Topic 5 Simple chemical reactions Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK Burning magnesium in oxygen ➜ Magnesium is an element, symbol Mg. ➜ Oxygen is an element, symbol O. In one molecule of oxygen there are two oxygen atoms. ➜ In one molecule of magnesium oxide there is one atom of magnesium and one atom of oxygen. Chemistry Topic 5 Simple chemical reactions Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK Burning magnesium in oxygen ➜ The word equation for this reaction is magnesium + oxygen → magnesium oxide ➜ Replacing the words with symbols: ➜ The number of atoms in the reactants and products is not correct. Chemistry Topic 5 Simple chemical reactions Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK Burning magnesium in oxygen ➜ The word equation for this reaction is magnesium + oxygen → magnesium oxide ➜ To balance the number of atoms in the reactants and products we need to write: Chemistry Topic 5 Simple chemical reactions Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK Balancing the equation for burning methane ➜ Methane is a fuel. When methane burns in oxygen, only carbon dioxide and water are produced. ➜ We can show the number and types of atoms in the reactants and products. Chemistry Topic 5 Simple chemical reactions Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK Balancing the equation for burning methane ➜ Methane is a compound, formula CH 4. ➜ In one molecule of oxygen there are two oxygen atoms. ➜ In one molecule of carbon dioxide there are one atom of carbon and two atoms of oxygen. ➜ In one molecule of water there are two atoms of hydrogen and one atom of oxygen. Chemistry Topic 5 Simple chemical reactions Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK Balancing the equation for burning methane ➜ The word equation for this reaction is methane + oxygen → carbon dioxide + water ➜ Atoms in the oxygen and methane molecules separate and rearrange to form molecules of carbon dioxide and water. ➜ Replacing the words with drawings of each atom: This doesn’t balance! Chemistry Topic 5 Simple chemical reactions Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK Balancing the equation for burning methane ➜ The word equation for this reaction is methane + oxygen → carbon dioxide + water ➜ To balance the number and type of atoms in the reactants and products we need to write: CH 4 + 2 O 2 → CO 2 + 2 H 2 O Chemistry Topic 5 Simple chemical reactions Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK Your task: Balance the following equations: N 2 + H 2 → NH 3 H 2 + O 2 → H 2 O Ca + O 2 → Ca. O Mg + H 2 SO 4 → Mg. SO 4 + H 2 CH 4 + O 2 → CO 2 + H 2 O H 2 + NO → H 2 O + N 2 HCl + Mg. O → Mg. Cl 2 +H 2 O Chemistry Topic 5 Simple chemical reactions Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK Your task: Answers: N 2 + 3 H 2 → 2 NH 3 2 H 2 + O 2 → 2 H 2 O 2 Ca + O 2 → 2 Ca. O Mg + H 2 SO 4 → Mg. SO 4 + H 2 CH 4 + 2 O 2 → CO 2 + 2 H 2 O 2 H 2 + 2 NO → 2 H 2 O + N 2 2 HCl + Mg. O → Mg. Cl 2 +H 2 O Chemistry Topic 5 Simple chemical reactions Science Progress © Hodder & Stoughton 2014
➜ SKILLS TASK Science Probe 10 Text Book Page 238 Complete Questions: 2 a, c, e 5 a, c, e 6 a, b, c, d, e, f, g 7 a, c, e, g 8 a, c, e, g, i Chemistry Topic 5 Simple chemical reactions
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