Answer:
SiO₂ + 4 HF -----> SiF₄ + 2 H₂O
Step-by-step explanation:
An equation is balanced when there is an equal amount of each element on both sides of the reaction. If these amounts are unequal, you can modify the quantities of particular molecules by adding coefficients.
silicon dioxide = SiO₂
hydrofluoric acid = HF
silicon tetrafluoride = SiF₄
water = H₂O
The unbalanced equation:
SiO₂ + HF -----> SiF₄ + H₂O
Reactants: 1 silicon, 2 oxygen, 1 hydrogen, 1 fluorine
Products: 1 silicon, 1 oxygen, 2 hydrogen, 4 fluorine
The balanced equation:
SiO₂ + 4 HF -----> SiF₄ + 2 H₂O
Reactants: 1 silicon, 2 oxygen, 4 hydrogen, 4 fluorine
Products: 1 silicon, 2 oxygen, 4 hydrogen, 4 fluorine