Chemical Reactions Quiz

What is a chemical reaction?

• A process that only involves physical changes

• A process in which substances change into new substances

• A process that never involves energy changes

• A process where elements disappear

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NGSS.MS-PS1-1

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What must be true for a chemical equation to be balanced?

• The number of atoms of each element is the same on both sides

• The total number of molecules is the same on both sides

• The reactants must be greater in mass than the products

• The reaction must release energy

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NGSS.HS-PS1-7

What does the arrow (→) in a chemical equation represent?

• The reaction moves in the opposite direction

• It shows the reaction is incomplete

• It indicates the formation of products

• It is a symbol for solid-state substances

In a chemical reaction, what does the symbol (s) represent?

• A gaseous substance

• A solid substance

• A liquid substance

• A dissolved substance

What is Avogadro’s number?

• 3.14 x 10²³

• 6.02 x 10²³

• 9.81 x 10²³

• 1.00 x 10²³

Why do chemists use the mole?

• To measure energy in a reaction

• To count particles in a substance

• To determine temperature changes

• To measure light absorption

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NGSS.HS-PS1-7

Which of the following is NOT a way to balance a chemical equation?

• Changing subscripts in the chemical formula

• Adjusting coefficients in front of compounds

• Ensuring equal numbers of atoms on both sides

• Using the law of conservation of mass

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NGSS.HS-PS1-7

If the mass of reactants is 75 grams in a reaction, what happens to the mass of the products?

• The mass of the products will be less than 75 grams

• The mass of the products will be more than 75 grams

• The mass of the products will be exactly 75 grams

• The reaction will not proceed

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NGSS.HS-PS1-7

What does heat above the reaction arrow (→) mean?

• The reaction requires heat to proceed

• The reaction releases heat as a product

• The reaction occurs at room temperature

• The reaction absorbs light

How many molecules are present in 2 moles of water (H₂O)?

• 6.02 x 10²³ molecules

• 1.20 x 10²⁴ molecules

• 3.01 x 10²³ molecules

• 2.00 x 10²³ molecules

Tags

NGSS.HS-PS1-7