Public Quiz: Unit 1 : Thermal Energy and Changes of Matter (Science) - Preparatory 2 - Science

Question 1

How does increasing the mass of a dissolved salt in a constant volume of solvent affect the thermal energy released or absorbed during dissolution?

The quantity of thermal energy is directly proportional to the mass of the dissolved salt.

The quantity of thermal energy is inversely proportional to the mass of the dissolved salt.

The relationship is exponential, not proportional.

The quantity of thermal energy remains constant regardless of the salt's mass.

Question 2

What salt is typically found in instant cold compresses, and what is its main function?

Magnesium sulphate, used to relieve muscle pain by widening blood vessels.

Ammonium Nitrate, used to reduce swelling by narrowing blood vessels.

Lithium Chloride, used to absorb moisture from the air.

Sodium Hydroxide, used to generate heat for warming.

Question 3

Nesting two polystyrene cups together would decrease thermal insulation during an experiment.

True

False

Question 4

Why is water not effective for extinguishing oil or petroleum fires?

Water instantly evaporates upon contact with burning oil.

Water reacts chemically with oil to produce toxic fumes.

Oil burns at a temperature too high for water to cool.

Oil floats on water and spreads the fire because its density is lower.

Question 5

Which characteristic correctly describes an exothermic reaction?

Maintains a constant temperature in the surrounding medium.

Absorbs thermal energy from the surrounding medium, causing its temperature to drop.

Converts all energy into light, with no heat released.

Releases thermal energy to the surrounding medium, causing its temperature to rise.

Question 6

What is the primary role of the compressor in a refrigerator's cooling cycle?

It expands the liquid refrigerant into a cold gas.

It releases heat into the refrigerator's interior.

It draws in and compresses the refrigerant gas, increasing its temperature.

It converts the hot gas back into a liquid state.

Question 7

What is the energy characteristic of the process of breaking chemical bonds?

It does not involve any energy change.

It is an exothermic process that releases heat.

It is an endothermic process that absorbs heat.

It is always accompanied by light emission.

Question 8

What is the safest procedure for diluting concentrated acids?

Adding water rapidly to the concentrated acid.

Pouring the acid directly into the center of the water.

Dripping the acid slowly onto the inner walls of the container holding the water.

Heating the acid before adding water to it.

Question 9

What characteristic is represented by an energy diagram for an endothermic reaction?

The activation energy is less than the total energy released.

The energy of the products is higher than the energy of the reactants.

The total energy of the system remains unchanged throughout the reaction.

The energy of the products is lower than the energy of the reactants.

Question 10

In an experiment designed to determine the thermal change accompanying dissolution where different masses of a salt are used, what typically represents the independent variable?

The mass of the solute

The change in temperature

The initial temperature of the water

The volume of water

Question 11

The compression stage in the refrigeration cycle causes the refrigerant gas's temperature to decrease.

False

True

Question 12

In the reaction CuO(s) + H2(g) → Cu(s) + H2O(v), which process does copper oxide undergo?

Reduction, because it loses oxygen.

Combustion, because heat is involved.

Oxidation, because it gains hydrogen.

Hydrolysis, because water is formed.

Question 13

What color is anhydrous cobalt chloride?

White.

Green.

Blue.

Pink.

Question 14

Anhydrous cobalt chloride is typically blue, while its hydrated form is pink.

True

False

Question 15

What is the ignition point of a fuel?

The temperature at which fuel turns into liquid.

The maximum temperature a fuel can withstand.

The temperature at which fuel becomes odorless.

The specific temperature at which fuel begins to burn.

Calculating your results... almost there!

Public Quiz: Unit 1 : Thermal Energy and Changes of Matter (Science) - Preparatory 2

How does increasing the mass of a dissolved salt in a constant volume of solvent affect the thermal energy released or absorbed during dissolution?

What salt is typically found in instant cold compresses, and what is its main function?

Nesting two polystyrene cups together would decrease thermal insulation during an experiment.

Why is water not effective for extinguishing oil or petroleum fires?

Which characteristic correctly describes an exothermic reaction?

What is the primary role of the compressor in a refrigerator's cooling cycle?

What is the energy characteristic of the process of breaking chemical bonds?

What is the safest procedure for diluting concentrated acids?

What characteristic is represented by an energy diagram for an endothermic reaction?

In an experiment designed to determine the thermal change accompanying dissolution where different masses of a salt are used, what typically represents the independent variable?

The compression stage in the refrigeration cycle causes the refrigerant gas's temperature to decrease.

In the reaction CuO(s) + H2(g) → Cu(s) + H2O(v), which process does copper oxide undergo?

What color is anhydrous cobalt chloride?

Anhydrous cobalt chloride is typically blue, while its hydrated form is pink.

What is the ignition point of a fuel?