The law of conservation of mass means that the atoms of an object cannot be created or destroyed, but can be moved around and be changed into different particles. This law says that when a chemical reaction makes two different atoms into a new product, the mass will be the same. Knowing this the mass of the copper should be the same at the beginning and at the end of the experiment.
In this investigation we will see some chemical changes such as formation of gas, temperature changes, solid formed, color change occurs or a new odor produced and physical changes such as freezing, melting, dissolving evaporating.
Copper is a widely used metal, it is use in door handles, cooking pots, cars, swimming pool and hot tubes to control the yeast.
Physical and chemical properties of copper:
• Symbol : Cu
• Atomic number: 29
• Highly electrical and thermal conductivity
• State at room temperature : Solid
• Brownish red colour
• Melting point : 1083 C
• Density : 8.93 g cm2
• Boiling point : 2595 C
Copper is find in ores, an ore is a type of rock that contains minerals with important elements including metals, there is a lot of different copper ores such as Chalcopyrite, Covellite, Malachite, Azurite:
|Mineral |Formula |Appearance |% copper in | | | | |mineral | |Bornite |Cu5FeS4 |Golden brown, metallic |63 | |Malachite |CuCO3Cu(OH)4 |Bright green, earthy |58 | |Azurite |2CuCO3Cu(OH)4 |Blue, glassy |55 | |Chalcopyrite |CuFeS2 |Golden yellow, metallic |35 |
Copper has bad toxic effects on plants, stunted root growth and leaf chlorosis are the two min symptoms, that’s why it is used as a fungicide. For humans, copper is part of the blood system, but a copper imbalance could be dangerous, and not very enjoyable. Firstly the nervous system dysfunctions, which could mean bipolar, depression, violence, fear… You could also get fungal and yeast infections much more easily. It also affects your reproductive system, infertility, miscarriage… A copper imbalance could also give you headaches, fatigue, insomnia, skin rashes...
• Stage 1:
Firstly weight the vial of copper given which was 11.5 g, then weight the empty vial which was 9.9 g. To know the mass of copper subtract those two numbers: 11.5 - 9.9 = 1.6. The mass of copper is 1.6g. it is solid, brown-orange colour, shinny, small and its shape is abnormal. The nitric acid is a transparent liquid, it looks like water. When pouring 15ml of the acid solution in the beaker the copper turns white then turquoise, it starts dissolving, bubbles are escaping from the copper, fuzzy looking brown toxic fumes is formed, it has a very strong odour. Add more acid if the copper isn’t fully dissolved, when it is the liquid is blue and there is no more copper.
A chemical reaction was formed since the liquid changed colour and there was a formation of a gas with a strong odour appeared. The copper didn’t disappear but it lost electrons and went into the solution.
• Stage 2:
The solution of sodium hydroxide is a transparent liquid, when slowly adding 40mL of this solution to the blue solution we obtained in the stage 1 the solution looks cloudy, heats up, smoke is coming out of the beaker and the solution is...