Chemistry Honors Practice Exam

Which statement best describes a reaction at dynamic equilibrium?

• The forward reaction stops as reactants are used up.

• The forward and reverse reactions occur at equal rates.

• The concentrations of products and reactants are equal.

• The concentration of products decreases as the reaction slows.

Tags

NGSS.HS-PS1-6

The table below provides data about a gas sample. Volume: 1.0 L Pressure: 303.9 kPa Temperature: 323 K Which of the following can be determined using the data?

• the chemical composition of the gas

• the condensation temperature of the gas

• the distance between gas molecules in the sample

• the number of moles of gas in the sample

Under special circumstances uranium 236 splits into krypton 91 and barium 142. Which type of energy is released in this process?

• chemical

• electrical

• kinetic

• nuclear

Tags

NGSS.HS-PS1-8

SpaceX rockets such as the "Raptor" engine used in the newest Starship use a mixture of ultra-chilled liquid methane and liquid oxygen, known as "methalox". The starting temperature of the O₂ (l) is no greater than −183°C and is combusted at nearly 5000°F. Which energy change occurs during the initial liftoff of this rocket?

• A. kinetic energy into potential energy

• B. chemical energy into kinetic energy

Tags

NGSS.HS-PS3-1

NGSS.HS-PS1-4

NGSS.HS-PS3-3

A student performs an experiment comparing the reactions of 1.0 M and 3.0 M hydrochloric acid with magnesium metal. Both 1.0 M and 3.0 M hydrochloric acid caused the magnesium metal to dissolve with the generation of bubbles and heat. There was visibly more magnesium metal remaining after 2 minutes in the 1.0 M hydrochloric acid solution.

• 1.0 M hydrochloric acid reacted faster with magnesium metal than 3.0 M hydrochloric acid because it acted as a catalyst.

• 1.0 M hydrochloric acid reacted faster with magnesium metal than 3.0 M hydrochloric acid because it raised the pressure of the system.

• 3.0 M hydrochloric acid reacted faster with magnesium metal than 1.0 M hydrochloric acid because it is a higher concentration.

• 3.0 M hydrochloric acid reacted faster with magnesium metal than 1.0 M hydrochloric acid because it raised the temperature higher.

Tags

NGSS.HS-PS1-5

How many moles are in 199 grams of CCl₄ (Carbon tetrachloride)?

• 0.77 mol

• 1.29 mol

• 3.06 × 10⁴ mol

• 3.31 × 10²² mol

CaCO3(s) + 2 HCl(aq) → CaCl2(aq) + H2O(l) + CO2(g) Which would increase the reaction rate between calcium carbonate and hydrochloric acid?

• increasing the concentration of calcium chloride

• decreasing the amount of hydrochloric acid

• crushing the calcium carbonate into a powder

• decreasing the concentration of hydrochloric acid

Tags

NGSS.HS-PS1-5

The graph below shows a phase diagram for water. Which phase change requires a decrease in kinetic energy?

• W

• X

• Y

• Z

Which of the energy level transitions would produce the highest energy photon?

• n = 6 → 2

• n = 5 → 2

• n = 4 → 2

• n = 3 → 2

Tags

NGSS.HS-PS4-1

What causes the emission spectrum of an element?

• movement of electrons from a lower energy state to a higher energy state

• movement of photons from a lower energy state to a higher energy state

• movement of electrons from a high energy state to a lower energy state

• movement of photons from a high energy state to a lower energy state

Tags

NGSS.HS-PS4-3