Question 1

Which of the following best describes a homogeneous mixture?

Accepted Answer

A mixture in which the composition is uniform throughout.

Question 2

Which of the following is an example of a physical change?

Accepted Answer

Dissolving sugar in water

Question 3

A sample of copper absorbs $$3.3 \ \mathrm{J} of $$heat, which increases its temperature by $$25 \ ^\circ \mathrm{C}. $$What is the mass (in g) of the copper sample if the specific heat capacity of copper is $$0.385 \ \mathrm{J/g} \cdot ^\circ \mathrm{C}$$?

Accepted Answer

$$0.34 \ \mathrm{g}$$

Question 4

Which of the following processes is an example of an exothermic reaction?

Accepted Answer

CO$$_2$$ burning

Question 5

Which of the following substances is a compound?

Accepted Answer

Ammonia, NH$$_3$$

Question 6

If $$15.7 \ \mathrm{g} of $$silver raises its temperature by $$17.2 \ ^\circ \mathrm{C}$$ when it absorbs $$649.5 \ \mathrm{J}$$, what is its molar heat capacity?

Accepted Answer

$$2.41 \ \mathrm{J/g} \cdot ^\circ \mathrm{C}$$

Question 7

Which of the following is NOT a physical property?

Accepted Answer

Rusting as it combines with aluminum

Question 8

A chemical reaction produces $$18.0 \ \mathrm{g} of $$water when $$2.0 \ \mathrm{g} of $$hydrogen gas reacts with $$16.0 \ \mathrm{g} of $$oxygen gas. Which law does this observation support?

Accepted Answer

Law of Conservation of Mass

Question 9

Which of the following best describes an amorphous solid?

Accepted Answer

A solid with no organized pattern or shapes

Question 10

Which of the following substances will have the lowest viscosity at room temperature?

Accepted Answer

Helium gas

Question 11

A refrigerator uses $$700 \ \mathrm{kWh} of $$electrical energy per year. How many kilocalories of electricity does it use in three years? ($$1 \ \mathrm{kcal} = 4184 \ \mathrm{J}$$, $$1 \ \mathrm{kWh} = 3.60 	imes 10^6$ \ \mathrm{J})$$

Accepted Answer

$$1800 \ \mathrm{kcal}$$

Question 12

Which of the following is NOT a chemical property?

Accepted Answer

It is very soluble in an acid solution.

Question 13

If $$120 \ \mathrm{g} of H$_2O $$cools from $$95 \ ^\circ \mathrm{C} to$$ $$45 \ ^\circ \mathrm{C}$$, how much heat (in J) is released? (Specific heat capacity of H$$_2O is$$ $$4.184 \ \mathrm{J/g} \cdot ^\circ \mathrm{C})$$

Accepted Answer

$$25,104 \ \mathrm{J}$$

Question 14

Which of the following is a reversible change?

Accepted Answer

Melting of ice

Question 15

A scientist observes that the final temperature of $$30.0 \ \mathrm{g} of $$metal at $$95.0 \ ^\circ \mathrm{C} in an $$insulated beaker containing $$65.0 \ \mathrm{g} of $$water at $$22.0 \ ^\circ \mathrm{C} is$$ $$28.0 \ ^\circ \mathrm{C}. If $$the metal gains $$11.1 \ \mathrm{J} of $$energy, from the information provided, determine the system and the surroundings.

Accepted Answer

System: metal; Surroundings: water

Question 16

Which of the following statements describes an endothermic reaction?

Accepted Answer

Absorbing heat and breaking bonds

Question 17

If the temperature of a water bath goes from $$25 \ ^\circ \mathrm{C} to$$ $$50 \ ^\circ \mathrm{C}$$, what can be said about the amount of heat?

Accepted Answer

It will double.

Question 18

Which of the following mixtures is hard to separate by chemical means?

Accepted Answer

Concrete

Question 19

Which of the following would have the greatest increase in temperature after absorbing $$25.0 \ \mathrm{J} of $$heat? (Refer to the specific heat capacities: Ag $$0.235 \ \mathrm{J/g} \cdot ^\circ \mathrm{C}$$, Cu $$0.385 \ \mathrm{J/g} \cdot ^\circ \mathrm{C}$$, ethanol $$2.46 \ \mathrm{J/g} \cdot ^\circ \mathrm{C}$$, wood $$1.76 \ \mathrm{J/g} \cdot ^\circ \mathrm{C})$$

Accepted Answer

$$25.0 \ \mathrm{g} Ag$$

Ch.3 Matter and Energy – Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard