Formulas and equations

Which formula represents calcium hydride?

• CaOH

• CaH₂

• CaH

• Ca(OH)₂

Which equation represents a physical change?

• 3O₂(g) → 2O₃(g)

• N₂(g) + 2O₂(g) → 2NO₂(g)

• H₂(g) + I₂(g) → 2HI(g)

• I₂(s) → I₂(g)

Tags

NGSS.MS-PS1-4

Given the equation representing a reaction: F₂(g) + 2KCl(aq) → 2KF(aq) + Cl₂(g) Which type of chemical reaction is represented by the equation?

• single replacement

• synthesis

• decomposition

• double replacement

Given the incomplete equation for a fermentation reaction: X → 2CH₃CH₂OH + 2CO₂ Which formula represents the missing reactant, X, in this equation?

• C₅H₁₂O₅

• C₆H₆O₅

• C₆H₆O₆

• C₆H₁₂O₆

Tags

NGSS.HS-LS2-3

NGSS.HS-LS2-5

Which sample of matter is classified as a mixture?

• SO₂(g)

• CH₃OH(ℓ)

• NaCl(s)

• KNO₃(aq)

What is a chemical name of the compound CuS?

• copper(I) sulfate

• copper(I) sulfide

• copper(II) sulfate

• copper(II) sulfide

Given the equation representing a reaction: 2NaCl → 2Na + Cl₂ Which type of reaction does this equation represent?

• decomposition

• single replacement

• synthesis

• double replacement

Which phrase describes a specific compound?

• can be physically separated into elements

• can contain only one element

• is composed of elements mixed in proportions that can vary

• is composed of elements chemically combined in a definite ratio

Given the equation representing a reaction: 2H₂(g) + 2NO(g) → N₂(g) + 2H₂O(g) What is the mass of N₂(g) produced when 1.0 gram of H₂(g) completely reacts with 15.0 grams of NO(g) to produce 9.0 grams of H₂O(g)?

• 7.0 g

• 14.0 g

• 28.0 g

• 25.0 g

Tags

NGSS.HS-PS1-7

Which formula is the empirical formula for ethane, C₂H₆?

• C₄H₁₂

• C₂H₆

• CH₃

• CH

Tags

NGSS.MS-PS1-1