Science Quiz: Weight, Changes, and Molecules

Questions and Answers

How is the weight of an object influenced when the gravitational force on the object is increased?

The weight increases (correct)

The weight decreases

It depends on the size of the object

The weight remains the same

The weight of an object is?

A measure of the object's density

None of the above

A measure of the gravitational force pulling the object toward the earth (correct)

The mass of the object multiplied by its volume

The fact that gold does not corrode is a?

Physical property

Chemical change

Chemical property (correct)

None of the above

Which of the following represents a physical change in matter?

A substance solidifies at 443K Signup and view all the answers

The melting of ice to liquid water is correctly classified as?

A physical change Signup and view all the answers

Which of the following is a chemical property of matter?

Flammability Signup and view all the answers

As two clear liquid solutions are added together, a red solid forms. This change is most likely?

A chemical change Signup and view all the answers

Which of the following substances are composed of heteroatomic molecules?

Water Signup and view all the answers

A molecule represented by O-O-O must be classified as?

Homoatomic and polyatomic Signup and view all the answers

Which of the following terms correctly applies to a molecule of CO2?

Triatomic, heteroatomic Signup and view all the answers

Table salt, NaCl is best classified as a(n):

Compound Signup and view all the answers

Homoatomic pure substances are known as:

Elements Signup and view all the answers

After heating, a pure substance, A, is found to produce both B and C. What can be said about the substance A?

It is a compound Signup and view all the answers

Which of the following is an example of a homogeneous mixture?

NaOH solution Signup and view all the answers

The basic unit of length in the metric system is the:

Meter Signup and view all the answers

Why is CaO the symbol for calcium oxide instead of Cao?

A capital letter means a new symbol Signup and view all the answers

What is the meaning of the two in ethyl alcohol, C2H5OH?

There are two carbon atoms per molecule of ethyl alcohol Signup and view all the answers

A molecular formula:

Is represented using the symbols of the elements in the formula Signup and view all the answers

What is meant by carbon-12?

The carbon atom has a relative mass of approximately 12 amu Signup and view all the answers

Refer to a periodic table and tell how many helium atoms (He) would be needed to get close to the same mass as an average oxygen atom (O)?

Four Signup and view all the answers

Determine the molecular weight of hydrogen peroxide, H2O2 in u.

34.02 Signup and view all the answers

Using whole numbers, determine the molecular weight of calcium hydroxide, Ca(OH)2.

74 Signup and view all the answers

Which of the following carries a negative charge?

An electron Signup and view all the answers

Which of the following is located in the nucleus of an atom?

Protons and neutrons Signup and view all the answers

Isotopes differ from each other in what way?

They have different numbers of neutrons in the nucleus Signup and view all the answers

The formula for dinitrogen monoxide is N2O. If a sample of the oxide was found to contain 0.0800 g of oxygen, how many grams of nitrogen would it contain?

0.140 Signup and view all the answers

What is the number of hydrogen atoms in a 18.016 gram sample of water?

1.204 x 10^24 Signup and view all the answers

What is the symbol for bromine?

Br Signup and view all the answers

What is the number of moles of water in one liter of water if one gram of water takes up one milliliter of space?

55.6 Signup and view all the answers

How many hydrogen atoms are in 1.00 mole of NH3?

18.1 x 10^23 Signup and view all the answers

Which of the following distinguishing electron configurations is characteristic of noble gases?

np^6 Signup and view all the answers

Which of the following would cause a calcium atom (Ca) to achieve a noble gas configuration?

Lose two electrons Signup and view all the answers

What is the formula weight of Ca(OH)2?

74.1 u Signup and view all the answers

Which of the following has a noble gas electronic configuration?

Both A and B Signup and view all the answers

When magnesium forms an ion, it would be represented as:

Mg^2+ Signup and view all the answers

Which of the following electronic changes will cause a Group VA (15) element to achieve a noble gas configuration?

Gain three electrons Signup and view all the answers

The ionic compound that forms between magnesium (Mg) and oxygen (O) has the formula:

MgO Signup and view all the answers

When an ionic compound forms between sodium (Na) and bromine (Br) atoms, it is true that:

A sodium atom donates an electron to a bromine anion Signup and view all the answers

The correct name for CeS is:

Cerium sulfide Signup and view all the answers

The rigid three-dimensional arrangement assumed by the ions of ionic compounds is called a:

Crystal lattice Signup and view all the answers

Which of the following would you expect to be the most polar molecule?

H2S Signup and view all the answers

Which of the following is a correct electron dot formula for a group IIIA (13) element M?

@M@ Signup and view all the answers

Which type of intermolecular forces leads to compounds with the lowest melting points?

Dispersion forces Signup and view all the answers

The correct name for K2SO4 is:

Potassium sulfate Signup and view all the answers

A polar molecule must have:

A positive and a negative end Signup and view all the answers

The correct name for KHPO4 is:

Potassium hydrogen phosphate Signup and view all the answers

Which of the following would be a polar molecule?

HCl Signup and view all the answers

What property of a liquid such as mercury is used in a liquid-in-glass thermometer?

Thermal expansion Signup and view all the answers

A gas sample is collected in a balloon. What happens to the density of the gas sample as the sample is heated?

Decreases Signup and view all the answers

Potential energy resulting from the attraction of particles:

More than one response is correct Signup and view all the answers

How does the kinetic energy of a particle change if the particle's velocity is increased by a factor of 3?

Kinetic energy increases by a factor of 9 Signup and view all the answers

Cohesive forces in matter are related to

Potential energy from particle attractions Signup and view all the answers

High density is characteristic of which state of matter?

More than one response is correct Signup and view all the answers

Definite shape is a characteristic of which state of matter?

Solid Signup and view all the answers

Small compressibility is a characteristic of which state of matter?

More than one response is correct Signup and view all the answers

Convert a temperature of 45 degrees Celsius into Kelvins

318K Signup and view all the answers

Increasing the pressure on a gas at a constant temperature does what to the volume of the gas?

Decreases Signup and view all the answers

2500 liters of oxygen gas is produced at 1.00 atm of pressure. It is to be compressed and stored in a 20.0 liter cylinder. If temperature is constant, calculate the pressure of the oxygen in the cylinder.

125 atm Signup and view all the answers

A 5.00 liter sample of gas measured at 27.0 degrees Celsius and 1.25 atm of pressure has a mass of 10.13 g. What is the molecular weight of the gas in u?

39.9 Signup and view all the answers

The force resulting from particle motion is referred to as:

Disruptive forces Signup and view all the answers

Near room temperature, air has a density of 1.18 x 10^-3 g/mL. What volume will 30.77 g of air occupy?

2.61 x 10^4 mL Signup and view all the answers

Which of the following correctly arranges the physical states of matter (gas -g, solid -s, liquid - l) in order of increasing energy of the particles (lowest to highest)?

s < l < g Signup and view all the answers

In an exergonic process, the system:

Loses energy Signup and view all the answers

At 20 degrees Celsius, a sample of solid spontaneously sublimes to a gas. This change in state is accompanied by which of the following changes in the solid sample?

Entropy and energy increase Signup and view all the answers

The concept of entropy:

Is employed as an indicator of disorder in a system Signup and view all the answers

Which of the following interpretations of the spontaneous chemical reaction is correct?

The entropy on the right of the equation is greater than that on the left Signup and view all the answers

Most automobiles function by burning gasoline by a process similar to the equation in which octane is burned: C8H18 + O2 ---> CO2 + H20 + heat (not balanced)

It explains why a car stops running when there is no gas in the fuel tank Signup and view all the answers

Which of the following states of matter generally has the lowest entropy?

Crystalline solid Signup and view all the answers

Catalytic action is:

Directly opposed by inhibitors Signup and view all the answers

Sulfur reacts with oxygen to produce sulfur dioxide, but only if the high activation energy is supplied. Which condition will lower the activation energy the most?

Using a catalyst Signup and view all the answers

The energy required to start some spontaneous processes is called:

Activation energy Signup and view all the answers

Which of the following will influence all reaction rates?

More than one response is correct Signup and view all the answers

Homogeneous catalysts are thought to function by:

Lowering activation energy of a reaction Signup and view all the answers

Study Notes

Weight and Gravitation

Weight increases with an increase in gravitational force on an object.
Weight is defined as the measure of the gravitational force pulling an object toward the Earth.

Chemical and Physical Changes

Gold’s resistance to corrosion is a chemical property.
A physical change is illustrated when a substance solidifies, such as at 443K.
Melting ice to liquid water is classified as a physical change.
Flammability is identified as a chemical property of matter.
The formation of a solid from two clear liquids indicates a chemical change.

Molecular Composition

Heteroatomic molecules include substances like water.
A molecule represented as O-O-O is classified as homoatomic and polyatomic.
Carbon dioxide (CO2) is triatomic and heteroatomic.
Table salt (NaCl) is classified as a compound, while homoatomic pure substances are known as elements.

Compounds and Mixtures

A pure substance that produces more than one substance upon heating is a compound.
An example of a homogeneous mixture is a sodium hydroxide solution.

Metric System and Chemical Formula

The basic unit of length in the metric system is the meter.
The formula for ethyl alcohol (C2H5OH) indicates two carbon atoms per molecule.

Molecular Weight and Moles

Molecular weight of hydrogen peroxide (H2O2) is approximately 34.02 u.
Calcium hydroxide (Ca(OH)2) has a molecular weight of 74 u.
One liter of water contains about 55.6 moles, and a sample of water weighing 18.016 grams has 1.204 x 10^24 hydrogen atoms.

Atomic Structure

Electrons carry a negative charge, while protons and neutrons are located in the nucleus of an atom.
Isotopes differ in the number of neutrons within their nucleus.

Reactions and Stoichiometry

The formula for dinitrogen monoxide (N2O) can be used to calculate nitrogen content based on oxygen mass.
Various conversions can determine gas properties such as density and molecular weight under specific conditions.

States of Matter and Energy

Experiments involving gas under pressure show that volume decreases with increased pressure.
The density of near room temperature air is approximately 1.18 x 10^-3 g/mL.

Chemical Kinetics and Thermodynamics

In exothermic processes, the system loses energy, while entropy is an indicator of system disorder.
Catalysts lower activation energy, facilitating reactions; inhibitors oppose this effect.

Properties of Matter

Solid matter has a definite shape and high density.
The melting states of matter are organized as solid < liquid < gas in terms of increasing particle energy.

Electronic Configurations and Ion Formation

Noble gases exhibit an electronic configuration characterized by np^6.
Atoms achieve noble gas configuration by electron transfer, such as calcium losing two electrons or group VA elements gaining three.

Chemical Reactions and Catalytic Action

The addition of catalysts will influence reaction rates and lower the activation energy necessary for reactions to occur.

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Description

Test your knowledge on topics of weight and gravitation, chemical and physical changes, and molecular composition. This quiz combines essential concepts from chemistry and physics, helping you understand how substances interact and transform. Dive in to see how well you grasp these fundamental ideas!