Chemistry Homework Help

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Physical & Chemical Changes

Q. 2.4) An example of a change where the chemical composition of a substance is not changed would be a) oxidation b) burning c) rusting d) melting

Solved • May 4, 2020

Physical & Chemical Changes

Q. In a laboratory experiment, a fermenting aqueous solution of glucose and yeast produces carbon dioxide gas and ethanol. The solution was heated by burning natural gas in a Bunsen burner to distill the ethanol that formed in the flask. During the distillation, the ethanol evaporated and then condensed in the receiving flask. The flame of the burner was kept too close to the bottom of the flask and some of the glucose decomposed into a black carbon deposit on the inside of the flask. During this experiment the following changes occurred. Which of these changes involved a physical change and not a chemical change? Check all that apply.

Solved • Mar 10, 2020

Physical & Chemical Changes

Q. Which of following changes that affect the composition of our atmosphere involve physical changes and which involve chemical reactions? Drag the appropriate items to their respective bins.

Solved • Mar 10, 2020

Physical & Chemical Changes

Q. Classify each of the following changes as physical or chemical. Drag the appropriate items to their respective bins.

Solved • Mar 10, 2020

Physical & Chemical Changes

Q. Which change is a chemical change? a) the corrosion of iron b) the forming of log in the morning c) the dissolving of sugar

Solved • Mar 10, 2020

Physical & Chemical Changes

Q. When the reaction occurs, two elements react to form a product. Which of the following best describes the product? 2 molecules of H2 gas + 1 molecule of O2 gas → 2 molecules of H20 gas a) A chemical element b) A chemical compound c) A heterogeneous mixture d) A homogeneous mixture

Solved • Jan 30, 2020

Physical & Chemical Changes

Q. Chemical reactions occur all around us. What other chemical reaction occurs in the video demonstration? 2 molecules H2 gas + 1 molecule of O2 gas → 2 molecules of H2O gas

Solved • Jan 30, 2020