Science Lab Report

1179 WordsJan 18, 20135 Pages
Research question Can heterogeneous mixtures be separated completely by using knowledge about the properties of matter (physical and chemical) Amount of water, and oil, and weight of nuts, pepper, iron fillings and dried apples Variables: Independent Variable- The weight of the items before the experiment Dependent variable- The weight of items after separating them from the mixture Controlled variable- The number of items, physical properties of items Hypothesis: I think that the weight of the items after separating will be different, because some of the items will soak the salty water and iron filings might stick to some other items, so the heterogeneous mixture can not be separated completely. Background information: When two or more different substances are combined, a mixture is formed. Mixtures can be homogeneous or heterogeneous. Homogeneous mixtures are uniform and have the same composition. Heterogeneous mixtures do not have the same composition and properties in their different parts and different parts in many cases could be visible. Solutions are homogeneous mixtures, for example salty water or tea or coke. Salads are heterogeneous mixtures. Milk is homogeneous mixture; under microscope separate particles can be seen: fat, protein, water, carbohydrates, vitamins and other substances. If different substances go through chemical changes/reaction then it is not a mixture but compound. Mixture can be separated by physical mean, while compound cannot be. Separation of mixtures by physical means include sieving, using magnets, evaporating, filtering and others. Solution is the type of homogeneous mixture where the size of particles is about the size of atoms and they cannot be visible. Colloids are also homogenous mixtures but the size of their particles is larger than in solutions: examples are milk or fog (Mixture 2003) Physical

More about Science Lab Report

Open Document