Question

this passage describes a chemical reaction. read the passage. then, answer the question below. computer microchips are created from sheets of silicon. these sheets often have an unwanted coating: a thin layer of silica (sio₂). this silica can be removed with hydrofluoric acid (hf). when hydrofluoric acid touches silica, the substances combine to form water (h₂o) and silicon tetrafluoride gas (sif₄). after the water and gas are removed, the silicon sheet can be processed into microchips. in the chemical reaction described in the passage, which of the following are reactants? select all that apply. silica (sio₂) hydrofluoric acid (hf) silicon tetrafluoride (sif₄) water (h₂o)

Explanation:

To determine reactants, we recall that reactants are substances that undergo a chemical reaction to form products. From the passage: "When hydrofluoric acid (HF) touches silica, the substances combine to form water (H₂O) and silicon tetrafluoride gas (SiF₄)". So HF and SiO₂ are the reactants (they start the reaction), while H₂O and SiF₄ are products (formed from the reaction).

Answer:

A. silica (SiO₂)
B. hydrofluoric acid (HF)