Chemical Equations

What is a chemical equation?

• gives instructions for naming compounds

• describes biological changes only

• describes chemical reactions

• shows how to write a chemical formula

What do you call the chemicals that are created in the reaction?

• Product

• Catalyst

• Substance

• Reactant

Consider the unbalanced equation: C₈H₁₆(g) + O₂(g) -> H₂O(g) + CO₂(g)

When the equation is completely balanced using the smallest whole numbers, the coefficient of CO₂ is _________.

• 1

• 8

• 12

• 16

When the equation Al(s) + O2(g) -> Al₂O₃(s) is correctly balanced using smallest whole numbers, the sum of the coefficient will be _______.

• 3

• 7

• 9

• 12

Consider the unbalanced equation: FeCl₂ + Na₂CO₃  -> FeCO₃ + NaCl. When the equation is completely balanced using the smallest whole numbers, the coefficient of NaCl is _________.

• 2

• 3

• 4

• 6

Consider the unbalanced equation: Li + N₂ -> Li₃N

When the equation is completely balanced using the smallest whole numbers, the coefficient of lithium is _________.

• 1

• 2

• 3

• 6

Consider the unbalanced equation: Ag + H₂S -> Ag₂S + H₂

What is the sum of the coefficients when the equation is completely balanced using the smallest whole-number equation?

• 5

• 6

• 7

• 8

Which of the following shows a correct way to balance the chemical equation:

Fe+Cl₂ -> FeCl₃

• 1Fe+2Cl₂ -> 1FeCl₃

• 1Fe+1Cl₂ -> 1FeCl₃

• 3Fe+1Cl₂ -> 2FeCl₃

• 2Fe+3Cl₂ -> 2FeCl₃

 Which four quantities are required to balance this equation?

aC₇H_8(g) + bO_2(g) --------> cCO_2(g) + dH₂O_(l)

• 2 9 4 8

• 1 5 7 4

• 2 10 8 14

• 1 9 7 4

Which four quantities are required to balance this equation?

aAl(OH)_3(s) + bHCl_(aq) -------> cAlCl_3(aq) + dH₂O_(l) 

• 2 6 2 3

• 1 3 1 6

• 1 3 1 3

• 2 3 2 3