13. Side view of a toy train engine: Side View of a Toy Train Engine
Train engine
2 newtons
5 newtons
A toy train engine rests motionless on a track. One student begins pushing the engine to the right with a
force of 2 Newton. At the same time, another student begins pushing the engine to the left with a force
of 5 Newton. Which of the following best describes the resulting?
A. It travels left at a constant speed.
B. It travels left at an increasing speed.
C. It travels right at a constant speed.
D. It travels right at an increasing speed.
1

Use examples from the article to explain one positive and one negative effect that chemistry has had on society.

One way in which the useful metal copper is produced is by dissolving the mineral azurite, which contains copper(ii) carbonate, in concentrated sulfuric acid. the sulfuric acid reacts with the copper(ii) carbonate to produce a blue solution of copper(ii) sulfate. scrap iron is then added to this solution, and pure copper metal precipitates out because of the following chemical reaction: (s) (aq) (s) (aq) suppose an industrial quality-control chemist analyzes a sample from a copper processing plant in the following way. he adds powdered iron to a copper(ii) sulfate sample from the plant until no more copper will precipitate. he then washes, dries, and weighs the precipitate, and finds that it has a mass of .

Scientists are often interested in knowing the molar heat of combustion – the heat released during the combustion of one mole of a substance. use the periodic table to find molar masses. how many moles of ethanol are present in the sample?