Fun with ScienceCam-Tu Diep

~Around 2/3 to ¾ of the earth surface is cover with water.

~Did you know that our bodies are made up of 65% water.

~75-80% of the human brain is water. ~The chemical name for water is H(2)O

- which represents two Hydrogen atoms and one Oxygen atom.

Did you know ?

1) Solid - frost , snow, ice.

2) Liquid – water, rain.

3) Gas - water vapour.

Water takes on three different forms

Liquid Density

Density is mass (how many atoms are in an object) divided by volume.

The more atoms a liquid contains the denser it will be.

Scientific Method

Regular Water Salt Water => Water + Salt Sugar water => Water + Sugar

Question & hypothesis: Will adding salt make water more dense? Will adding sugar make water more dense? Which is denser, sugar water or salt water? Write down what you think will happen to the density of water if you add salt or sugar.

*Hypothesis: is a proposed explanation for a phenomenon.

Which is more dense?

Fill three beakers with 150 ml (2/3 cup) of water. Add food coloring to make blue, red, and green water.

Add 2 teaspoons of salt to the blue beaker and stir until the salt is dissolved. Add 2 teaspoons of sugar to the yellow water and stir until it is dissolved.

Try putting a raisin in each of the beakers. Does it float? Remove the raisins with a spoon.

Pour some of the blue (salty) water into the graduated cylinder. Using the pipet, slowly add the yellow (sugar) water one or two drops at a time. Record which sinks to the bottom and which floats on top.

Add the red (pure) water drop-by-drop to the other two and record what happens.

Procedure:

Were your predictions correct? Did adding salt and sugar to the water make the water more dense or less dense? Which was more dense, the salt water or the sugar water?

Conclusions:

Water Facts and Trivia

Do you know your facts?

H+ (aq) + OH− (aq)  H2O acid + base → salt + water

CH3CO2H + NaHCO3 => CH3CO2Na +H2O+CO2 (formed from unstable carbonic acid H2CO3)

Vinegar + baking soda =>Sodium acetate +water + carbon dioxide

Sodium bicarbonate and vinegar => Sodium acetate and water and carbon dioxide

NaHCO3 + CH3COOH => CH3COO-Na+ + H2O + CO2

The positive ion from a base forms a salt with the negative ion from an acid.

Acid Base Reaction

Baking soda is made of sodium bicarbonate. Vinegar is an acid (acetic acid). When the two combine, they create a chemical reaction (Acid-base Reaction). Vinegar causes the baking soda to break down, creating a different substance. This gas is called carbon dioxide. It is less dense than the air around it. The carbon dioxide rises into the balloon, inflating it.

Conclusion