I am currenty working on my AP Chem Summer Project, but I need a little help.
Which of the following are pure substances, and which are homogeneous mixtures? a) sugar dissolved in water; b) tea and ice; c) french onion soup; d)mud; e) gasoline; f) carbon dioxide; g) a chocolate chip cookie.
A sugar solution is a homogeneous mixture. A mixture of tea and ice (I assume you mean a tea extract and not leaves of tea) certainly isn't homogeneous is it? Can't you see the ice cubes floating around? And can't you scoop out an ice cube? (You can scoop out a molecule of sugar.). Look at french onion soup and make your decision. Mud will settle out and I can feel gritty material in mud. Gasoline, I suppose we could call pure but it isn't one substance but a blend of hydrocarbons and these days has alcohol added. CO2 is a pure substance. A chocolate chip cookie is not.
To determine which substances are pure substances and which are homogeneous mixtures, you need to understand their definitions.
1. Pure substance: A substance that consists of only one type of element or compound. It has a fixed composition and consistent physical and chemical properties throughout.
2. Homogeneous mixture: A uniform mixture where the components are evenly distributed and blended together, resulting in a consistent composition throughout.
Now, let's analyze each option:
a) Sugar dissolved in water: This is a homogeneous mixture. When sugar dissolves in water, it forms a solution where the particles of sugar are evenly dispersed throughout the water.
b) Tea and ice: This is also a homogeneous mixture. When ice is added to tea, it melts and forms a solution, resulting in a uniform mixture.
c) French onion soup: This is a homogeneous mixture. In French onion soup, various ingredients like onions, broth, and spices are mixed together to form a consistent composition throughout.
d) Mud: Mud is typically a heterogeneous mixture, meaning its composition is not uniform throughout. It consists of various components like soil, water, minerals, and organic matter, which are not evenly blended together.
e) Gasoline: Gasoline is a homogeneous mixture. It is made up of several different hydrocarbons, but these components are evenly mixed together to form a consistent composition.
f) Carbon dioxide: Carbon dioxide is a pure substance. It consists of only one type of molecule, composed of one carbon atom bonded to two oxygen atoms. It is a chemical compound, so it's considered a pure substance.
g) A chocolate chip cookie: A chocolate chip cookie is a heterogeneous mixture. It contains various components like flour, sugar, chocolate chips, and butter, which are not evenly distributed and can be distinguished visually.
In summary:
Pure substances: Carbon dioxide (f)
Homogeneous mixtures: Sugar dissolved in water (a), tea and ice (b), French onion soup (c), gasoline (e)
Heterogeneous mixtures: Mud (d), chocolate chip cookie (g)