R: WW- Writing and Balancing Chemical Equations

Which of the following changes would you consider to be a chemical change?

• A. Candle wax solidifies when it is cooled.

• B. Baking soda is combined with vinegar

• C. Ice melts.

• D. Paper turned into pieces.

All of the following are chemical reactions EXCEPT ___

• A. burning of paper

• B. potassium fluoride and calcium nitrate are mixed.

• C. sodium hydroxide is added to nitric acid

• D. freezing of potassium nitrate solution.

The correct coefficients for the equation are

• A. 2, 2, 3

• B. 3, 2, 2

• C. 2, 3, 2

• D. 2, 1, 3

Balancing a chemical equation involves ____

• A. adjusting the subscripts

• B. adjusting both subscripts and coefficients

• C. adjusting the coefficients

• D. adjusting the masses of reactants and products

Tags

NGSS.HS-PS1-7

What is the meaning of the illustration as used in a chemical equation?

• A. yields

• B. reacts with

• C. heat is applied

• D. gas

Refer to the chemical equation to answer questions 6-8.How many moles of S is needed to form 2 moles of SO3?

• A. 1

• B. 2

• C. 3

• D. 6

How many moles of O2 are needed to give 4 moles of SO3?

• A. 3

• B. 2

• C. 6

• D. 4

How many moles of oxygen atoms are there in 1 mole of oxygen molecule?

• A. 6

• B. 3

• C. 1

• D. 2

In a chemical reaction, the mass of the products is _____

• A. less than the mass of the reactants.

• B. greater than the mass of the reactants.

• C. equal to the mass of the reactants.

• D. undetermined

Tags

NGSS.HS-PS1-7

Which of these is incorrect interpretation of this balanced equation?

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