Indicators of Chemical Reactions

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Evidence of a chemical reaction is anything that shows - a new substance has formed, a solid dissolved in a liquid, interaction between 2 gases, a change in the state of matter

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a new substance has formed

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All of the following are indicators of a chemical reaction except one. Which one is NOT an indicator that a chemical reaction has taken place? Options: the production of heat or light, a color change, the production of gas bubbles, the dissolving of one substance in another

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the dissolving of one substance in another

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A student places a piece of a potato into a container of hydrogen peroxide and observes bubbles forming around the potato. The presence of bubbles might indicate the formation of a new substance because bubbles -

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could show that a gas is forming

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A clear liquid from a flask is poured into another clear liquid in a beaker. Which of the following results of this procedure would indicate a new substance was formed? The level of the substance in the beaker is higher after the other liquid is added. A yellow solid precipitate forms and then settles to the bottom of the beaker.

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A yellow solid precipitate forms and then settles to the bottom of the beaker.

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Which of the following describes a precipitate? Options: a liquid forms when a block of metal is heated, a solid forms when one liquid is poured into another, a gas forms when a solid is placed in a liquid, bubbles form when an acid is poured on a rock

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a solid forms when one liquid is poured into another

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In an exothermic reaction, energy is _________.

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Released

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What indicators of a chemical change were shown when a white baking soda solution was combined with white calcium chloride, resulting in an increase in temperature, bubbling, and a white color?

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Temperature increase and bubbling/fizzing

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Which of the following is an example that includes evidence of a chemical reaction? A sample of zinc is placed in water and it settles to the bottom, A solid block of ice is heated and it completely melts into a liquid., Sugar that is burned gives off an odor and turns brown and then black., A tomato is placed into a blender and chopped up into smaller pieces.

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Sugar that is burned gives off an odor and turns brown and then black.

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What is the left part of a chemical equation called?
H_{2 +} O → H₂O

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Reactants

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2H₂ + O₂ ----> What is the product?

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2H₂O