1. You mix solution A with solution B in a beaker. Which of the following observations does not help you prove that a chemical reaction has occurred?

• A. The beaker becomes warm.

• B. You see gas bubble out of solution.

• C. Solution A, solution B, and the mixture are all yellow.

• D. None of the above; all help prove that a chemical reaction has occurred.

2. In the reaction described by the word equation:

sodium + water ------> sodium hydroxide + hydrogen gas

• A. Sodium hydroxide is a product.

• B. Sodium is a product.

• C. Water is a reactant.

• D. Both (A) and (C)

Tags

NGSS.MS-PS1-2

3. Which of the following indicates that a chemical equation is balanced?

• A. The numbers of atoms of each element are the same on both sides of the equation.

• B. All of the coefficients are the same.

• C. The numbers of molecules on each side of the equation are equal.

• D. The sums of the coefficients on each side of the equation are equal.

Tags

NGSS.HS-PS1-7

4. From a complete and correctly written chemical equation, you can obtain the

• A. Chemical formulas of the reactants and products.

• B. Relative amounts of the reactants and products.

• C. Physical states of the reactants and products.

• D. All of the above

5. To balance a chemical equation, you must

• A. Adjust the subscripts.

• B. Adjust the number of products.

• C. Adjust the number of reactants.

• D. Adjust the coefficients.

Tags

NGSS.HS-PS1-7

6. The formation of a solid product in a chemical reaction is represented by the symbol

• A. (Aq)

• B. (G)

• C. (L)

• D. (S)

Tags

NGSS.MS-PS1-2

7. In the expression 3CO₂, the numbers 3 and 2 are, respectively,

• A. A subscript and a coefficient.

• B. A coefficient and a subscript.

• C. Two subscripts.

• D. Two coefficients.

Tags

NGSS.MS-PS1-1

8. What is the total number of molecules that is represented by the following chemical equation?

NH₄NO₂ --------> N₂ + 2H₂O

• A. 3

• B. 4

• C. 8

• D. 16

Tags

NGSS.HS-PS1-7

9. Which equation below violates the law of conservation of mass?

• A. 2H₂ + O₂ ---------> 2H₂O

• B. KCl + Br ----------> KBr + Cl₂

• C. 2Fe₂O₃ + 3C -------------> 4Fe + 3CO₂

• D. Na₂CO₃ + 2HCl --------------> 2NaCl + H₂O + CO₂

Tags

NGSS.HS-PS1-7

10. Which of the following equations represents the balanced equation for the reaction of iron and oxygen?

• A. 2Fe + O₂ ----------> Fe₂O₃

• B. Fe + 3O₂ ------------> Fe₂O₃

• C. 4Fe + 3O₂ ----------> 2Fe₂O₃

• D. 3Fe + 3O₂ ------------> 2Fe₂O₃

Tags

NGSS.HS-PS1-7