Science Investigations: Pure Substances and Mixtures

Science Investigations #1

Concentrating a Mixture (Page 188)

Question: What factors affect the concentration of a Mixture?

Hypothesis: a) Adding more solute (marbles) to the mixture will increase teh concentration of a mixture

b) Decreasing the amount of solvent (sand) will increase the concentration of the mixture:

Procedure: - Measure and record the mass of a empty beaker (250 ml)

- Measure the mass of the beaker and marbles on a scale.

- Record the mass of the Marbles (solute)

- Measure the mass of the Sand (solvent) and Beaker

- Record the mass of the sand (Solvent)

- Repeat the steps using a greater quantity of marbles (solute)

- Repeat the steps decreasing teh amount of sand (solvent)

Observation:

Mass of Beaker Number of Mass of Volume of Mass of Mass of Marbles Concentration

Marbles Marble(s) Sand Sand ÷ Mass of sand (percent) %

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110 g 1 6 200 ml 230 g 0.026 2.6%

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110 g 2 12 200 ml 230 g 0.052 5.2%

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110 g 3 18 200 ml 230 g 0.075 7.5%

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110 g 4 24 200 ml 230 g 0.104 10.4%

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110 g 1 6 100 ml 115 g 0.052 5.2%

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110 g 2 12 100 ml 115 g 0.104 10.4%

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110 g 3 18 100 ml 115 g 0.156 15.6%

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110 g 4 24 100 ml 115 g 0.208 20.8%

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Conclusion: refer back to your hypothesis

Questions #1,2,3 Page 188