Calcium By: Erica, Nicole & Leighara

Properties Chemical Physical Fairly soft Shiny silver surface when cut Calcium surface becomes dull upon contact with oxygen forming a white/ grey calcium oxide Density – 1.54g/cm^3 MP – 850 C BP – 1440 C Active- reacts with oxygen Reacts with Halogens Reacts with cold water, most acids and most non-metals. Example: sulfur phosphorous

Hypothesis As a group, we predicted that using calcium as a reactant would produce a base. We predicted this because of previous research before beginning our experiment. Back in our notes, we saw an example of this type of reaction. We knew that calcium resides within us, so it can’t be a dangerous metal but can still react in some way. This is when we concluded it was a base.

Acid or Base?

Formula: metaloxide + water  base We came up with this formula from our notes (Types of Reactions). From looking at a synthesis reaction, we discovered that a metal + oxygen = a metaloxide. From there, adding water with a metal oxide produces a base. The equation is: CaO(s) + H2O(l)  Ca(OH)2 (aq) Therefore, BASE !

Materials Procedure 100 mL test tube Weigh boat Scoopula Graduated cylinder 100 mL beaker pH strip Calcium water Procedure Measure 10mL of water in a test tube. Add a dash of calcium to the water. Allow time for the calcium to react with the water. Place a pH strip into the 100 mL beaker. Pour the solution on the strip. What colour does it turn? Check the pH scale to determine if an acid or a base was produced.

How did ours react ? In the bottle, the calcium appeared to be white/grey. This was due to the oxygen contact. However, underneath the white calcium, the solid appeared to look almost black. This was because it was not exposed to the air. When we added the calcium to the water, it hesitated for a few seconds then started to form a gas. The pieces of calcium floated to the top, while continuing to form its gas. The water then began to form a white layer on top of the water. Nicole shook it a bit to see if it would do anything else, and the water turned completely to an opaque substance.

PPP and PPE Clean spills Wash hands Have hair tied back Air exchange vents / fume hood Apron Goggles

Evidence

Referring back to our hypothesis, we were correct Referring back to our hypothesis, we were correct. The product was a base. We figured this out by first using our notes. Mrs. Coristine provided us with an exact example of the reactant calcium going through the stages of becoming a base. We also knew this from testing the product with a pH strip. When we performed this experiment, the strip turned to a purple colour. Referring back to the pH scale, purple was the highest colour with a pH level of 13. This means the solution is a base. Lastly, going into our resource book, the reaction chart showed us just this. Calcium is part of the first 8 chemicals that have a strong reactivity. Those chemicals mix with oxygen to first create peroxides. Then when added to water, it creates a gas. This sums up all of our reasoning for why this product is a basic solution. Therefore, Calcium is a BASE!