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Lab notes for Chem Lab...

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Experiment #1:        

Mass of empty crucible (g) o 35.000g (b) mass of crucible and Mg (g) before heating o 40.000g Mass of the "unknown" product and crucible after heating (g) o 43.291g (b) change in mass (g) o 3.291g Since magnesium oxide was formed, the extra mass came from the new product. Assuming all the magnesium reacted in the reaction, the total mass the product formed was 8.291g. The matter burned a little. After heating, the mass of the contents in the crucible increased. It went from 40.000g to 43.291g.

Experiment #2:    

Mass of empty crucible (g) o 35.000g +5g of copper (II): 40.000g After copper (II) carbonate hydroxide was heated, it turned black, therefore, the copper compound was cuo. Given that the mass was lost from copper(II) carbonate, the moles of product produced was a total of 40.948 g/mol. o 3.327 g Copper carbonate hydrate/79.545 g/mol o = 0.042 mol Copper carbonate hydrate o 0.042 mol Copper carbonate hydrate * 1 mol of water /1.0 mol Copper carbonate hydrate o = 0.042 mol of water o 0.042 mol of water * 18.015 g/mol o = 0.75 g water

Experiment #3:    

Mass of flask: o 94.000g +15mL of 6M (Hcl): o 110.624g Thermometer: o 21.5°C +.20 of zinc: o Pressure: 1.442atm

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Volume of gas: o 73.63mL

Experiment #4:   

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Volume of sodium hydroxide: o 150ml (color was clear) Volume of nickel chloride: o 50mL (color was green) When the hydrochloric acid and zinc were combined, the mixture bubbled, the pressure increased from 1 atm to 1.71 atm, and the temperature increased from 21.5 to 26.5 degrees Celsius. When zinc and hydrochloric acid combined, pressure increases which indicates that there is an evolution of gas. Since temperature also increased, this indicates that the reaction is exothermic. When solutions of naoh and nicl2 are combined, Ni becomes solid. The ions present in an aqueous solution of naoh are Ni+2 and Cl-. The ions present in an aqueous solution of naoh are Na+ and OH. Synthesis reaction: nicl2+2 H2O Ni(OH)2+2hcl Decomposition reaction: Cu2CO3(OH)2. H2O ---- 2cuo + CO2 + 2H2O Single displacement: Zn (s) + 2hcl (aq) --- zncl2 (s) + H2 Double displacement: nicl (aq) + 2naoh (aq) ---- Ni(OH)2 (s) + 2nacl (aq)...