Lab_report 4

Prelab questions: • In forming compounds does a calcium atom gain or lose electrons? In the formation of the compound ( ?𝑎 + 𝐻 2 ? 𝑦𝑖?𝑙?𝑠 → ?𝑎(?𝐻) 2 + 𝐻 2 ) the calcium goes from charge 0 (element does not have any charge) to charge + 2 so its loosed electrons. • How many electrons? It lost 2 electrons. • What is the charge of the hydroxide ion? The charge of hydroxide ion is -1 • What would you predict for the chemical formula of calcium hydroxide? ?𝑎(?𝐻) 2 • Does the calcium hydroxide compound have charge? No, the calcium hydroxide compound has no charge. 2. Balanced the equations • 2?𝑎(𝑠) + 2𝐻 2 ? (?) 𝑦𝑖?𝑙?𝑠 → 2?𝑎?𝐻(𝑎𝑞) + 𝐻 2 (?) • 2?𝑎(𝑠) + 2𝐻?? (𝑎𝑞) 𝑦𝑖?𝑙?𝑠 → 2?𝑎??(𝑎𝑞) + 𝐻 2 (?) 3. How many moles of 𝐇 ? will be produced if 15.0g of Na reacts completely with excess HCl? Moles of Hydrogen: 15.0 g Na ∗ 22.99 mol Na 15g Na ∗ 1 mol H 2 2 mol Na = 0.326 mol H 2 4. In this experiment a sample of calcium reacts with water to produce calcium hydroxide and hydrogen gas. 1. The solution is titrated with HCl. Write the net ionic reaction that occur. Chemical formula: ?𝑎(?𝐻) 2 + 2𝐻?? 𝑦𝑖?𝑙?𝑠 → ?𝑎?? 2 + 2𝐻 2 ? Ionic equation: ?𝑎 2+ + 2?𝐻 − + 2𝐻 + + 2?? − 𝑦𝑖?𝑙?𝑠 → ?𝑎 2+ + 2?? − + 2𝐻 2 ? Net ionic equation : ?𝐻 − + 𝐻 + 𝑦𝑖???𝑠 → 𝐻 2 ?