Chem 110 - Test 2

Which of the following parts of Dalton's atomic theory has been modified in light of later discoveries? A) Atoms are indivisible B) Chemical reactions involve rearrangement of atoms C) All matter is made up of very small particles called atoms D) Compounds are formed from atoms

A) Atoms are indivisible

Mendeleev's periodic table organized elements in a systematic way. Which of the following attempted to arrange elements in a systematic way and can be considered a "precursor" of the modern periodic table? A) Dobereiner's Triads B) Dalton's Atomic Theory C) Dalton's Atomic Masses D) Berzelius's Atomic Weights

A) Dobereiner's Triads

The ancient Greeks believed that matter was composed of four basic elements. Which of the following was NOT one of the four? A) Mercury B) Water C) Earth D) air

A) Mercury

Methane can be decomposed into two simpler substances, hydrogen and carbon. Therefore, methane

cannot be an element.

Lavoisier measured the mass of substances before and after chemical reactions and summarized his observations in a(n)

law.

Nitrogen forms a number of different compounds with oxygen, depending upon the experimental conditions. This type of observation concerning the behavior of matter is summarized by

the Law of Multiple Proportions.

Lavoisier performed many of the same experiments as his predecessors. The one thing that most distinguished Lavoisier's work was

the mass measurements

Perhaps the greatest triumph of Mendeleev's periodic table was

the prediction of the existence of undiscovered elements

After many observations, Proust stated that elements combine in definite proportions to form compounds. Dalton explained these observations by proposing that matter must consist of atoms Dalton's explanation is called a(n)

theory

The Greek word for atomos means

uncuttable

32 g of sulfur will react with 48 g of oxygen to produce 80 g of sulfur trioxide. If 16 g of sulfur and 100 g of oxygen are placed into a sealed container and allowed to react, what is the mass of the material in the container after the reaction is completed?

116 g

How many years ago was an atomic view of matter first proposed?

2500

Assume that you have a new "triad" of elements (A,B,C) with similar properties. A is the smallest element and has a mass of 30 u. C is the largest element and has a mass of 90 u. The mass of B would be approximately __________ u.

60

Which one of the following statements is NOT a correct statement of the Law of Conservation of Mass? A) The mass of a system is dependent upon chemical reactions that may occur B) Matter cannot be created nor destroyed C) Atoms are conserved in chemical reactions D) The mass of a system is conserved in a chemical reaction

A) The mass of a system is dependent upon chemical reactions that may occur

Which philosopher believed that matter was continuous and was not made up of atoms?

Aristotle

Although all parts of Dalton's atomic theory are important, which one of the postulates is crucial to explain the observations summarized by the Law of Definite Proportions?

Atoms combine with other atoms in fixed, whole number ratios to form compounds

Leucippus and Democritus believed that all of the following statements about matter were true EXCEPT A) Substances are mixtures of different kinds of atoms B) Matter was continuous C) Each type of matter had distinctive size and shape D) Matter was made up of atoms

B) Matter was continuous

The scientist who in 1828 published a table of atomic weights containing 54 elements was

Berzelius

Which of the following was NOT explained by Dalton's atomic theory? A) the difference between elements and compounds B) the Law of Conservation of Mass C) the difference between isotopes of an element D) the Law of Multiple Proportions

C) the difference between isotopes of an element

Which of the following postulates of Dalton's atomic theory has been modified in light of later discoveries? A) Chemical reactions involve rearrangement of atoms B) Compounds are formed from atoms C) All matter is made up of very small particles called atoms D) All atoms of an element are identical

D) All atoms of an element are identical

___ was the first person to propose a consistent "modern" atomic theory

Dalton

No matter how much extra oxygen is available, 12 grams of carbon always combines with 32 grams of oxygen. This best illustrates the Law of

Definite Proportions.

The "father of modern chemistry" is

Lavoisier

The Law of Definite Proportions was first stated by

Proust

CO2 always contains 3 g of C for every 8 g of O. This is an example of

Proust's Law of Definite Proportions

(True/False) Democritus thought that real substances were mixtures of various types of atoms.

True

(True/False) Dobereiner's Triads and Mendeleev's Periodic Table were both based on the idea that properties of elements tended to repeat.

True

(True/False) Germanium was discovered in 1886. Its existence had been predicted by Mendeleev

True

(True/False) The Law of Constant Composition and the Law of Definite Proportions are different names for the same phenomenon

True

Mendeleev arranged elements in the periodic table primarily in order of their

atomic masses

The amount of carbon on the earth, including the atmosphere,

is essentially constant

Atoms of the same element that have different masses are called

isotopes

If drops of water are subdivided to the ultimately smallest drops possible, what is the smallest particle of water that retains the chemical and physical properties of water?

molecule.

Leucippus and Democritus proposed the "first" atomic view of matter. They arrived at this view based on

philosophical and intuitive speculation.

When Mendeleev developed his periodic table, he placed the greatest emphasis on

putting elements with similar properties in the same column