Chemistry Regents Review

Which elements combine by forming an ionic bond?

• sodium and potassium

• sodium and oxygen

• carbon and oxygen

• carbon and sulfur

Tags

NGSS.HS-PS1-3

The bonds between hydrogen and oxygen in a water molecule are classified as

• polar covalent

• nonpolar covalent

• ionic

• metallic

The degree of polarity of a chemical bond in a molecule of a compound can be predicted by determining the difference in the

• melting points of the elements in the compound

• densities of the elements in the compound

• electronegativities of the bonded atoms in a molecule of the compound

• atomic masses of the bonded atoms in a molecule of the compound

Tags

NGSS.HS-PS1-1

A 1.0 mole sample of Krypton gas has a mass of

• 19 g

• 36 g

• 39 g

• 84 g

Standard pressure is equal to

• 1 atm

• 1 kPa

• 273 atm

• 273 kPa

As the temperature of a substance decreases, the average kinetic energy of its particles

• decreases

• increases

• remains the same

Tags

NGSS.HS-PS3-2

Which Celsius temperature is equal to 298 K?

• 25

• 273

• 298

• 571

Which process is a chemical change?

• condensation of H₂O(g)

• synthesis of MgO(s)

• evaporation of C₂H₅OH(l)

• sublimation of CO₂(s)

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A collision between reactant particles is most likely to result in a reaction when the particles have proper orientation and proper

• charge

• energy

• mass

• radius

Given the equation representing a system at equilibrium:

2NO₂(g) ⇌ N₂O₄(g)

Which statement describes this reaction at equilibrium?

• The concentration of the reactant and the product must be equal.

• The concentration of the reactant and the product must be constant.

• The rates of the forward and reverse reactions are increasing.

• The rates of the forward and reverse reactions are decreasing.