Chem Final

Which expression represents the percent by mass of nitrogen in NH4NO3?

B (Cant input expression)

Which of the following groups of the periodic table contains ONLY metals?

Group 1B (11)

Which of the following shows the correct number of valence electrons for the corresponding atom?

I: 7

Hydrogen bonding accounts for which of the following properties of water? I. low boiling point II. high surface tension III. low vapor pressure

II and III

Which line on the periodic table separates the metals from the nonmetals and metalloids?

III

Electronegativity

generally decreases from left to right across a period.

All of the following are characteristics of ionic compounds EXCEPT

having a low melting point.

What type of bond is represented by the dotted line between the two molecules in this figure? (Note that the types of atoms are designated.)

hydrogen (Still can't put in image)

The category of elements that is characterized by the filling of f orbitals is the

inner transition metals.

Which element has an electron configuration that makes it unlikely to react with other atoms?

krypton (Kr)

Which element, when combined with chlorine, would most likely form an ionic compound?

lithium

The melting and boiling points of most molecular compounds are

lower than those of most ionic compounds

The majority of the elements on the periodic table are

metals

Where on the periodic table would you find non-metallic elements?

on the right side of the table

What type of substance is shown in the diagram?

salt crystal (Can't put in image)

Which atom's electron dot structure shows six valence electrons?

sulfur

A covalent bond forms

when atoms share electrons.

Which of these elements is NOT classified as a lanthanide?

yttrium

Which molecule can be represented by this geometric structure? (Cant put in pic sorry)

CH4

What is the empirical formula of a compound that is 3.05% carbon, 0.26% hydrogen, and 96.69% iodine?

CHI3

Among the elements listed, which would show the largest increase between the second and third ionization energies?

Ca

Which statement best describes the periodic law?

When elements are arranged in order of increasing atomic number, there is a periodic repetition of their physical and chemical properties.

How many moles of gold, Au, are in 4.18 × 1023 atoms of gold?

0.694 mol

Standard temperature is

0°C

Use VSEPR theory to predict the bond angles of sulfur hexafluoride, SF6.

90°

Which phrase does NOT describe a molecular compound?

consists of atoms from a metal and a nonmetal

Metals are good conductors of electricity because they

contain mobile valence electrons.

A chemical reaction produces 5.44 L of carbon dioxide at STP. How many moles of carbon dioxide are produced by the reaction?

0.243 mol

How many moles of potassium permanganate, KMnO4, are in 2.25 L of a 0.300M potassium permanganate solution?

0.675 mol

Magnesium chloride is a naturally occurring element and is extracted from salt water solutions, such as sea water. It is environmentally safe and has many uses, which is one of the reasons why it is used for dicing highways and airport runways. Calculate the number of moles in 1.02 g of MgCl2.

1.08 × 10−2 mol

Which of the following does NOT contain the same number of atoms as 12.0 g of carbon?

2.0 g H2

About how many moles is 1.2 × 1018 atoms of tin?

2.0 × 10-6 moles

Zinc, Zn, is typically used in the manufacturing of dyes, paint, wood preservatives, and rubber. How many moles of zinc is 1.35 × 1020 atoms of zinc?

2.24 × 10-4 mol Zn

Argon, Ar, is a noble gas that is colorless, odorless, and tasteless. It makes up 0.934% of air. Find the number of moles in 200 L of argon gas at STP.

2.24 × 103 mol Zn

At STP, what is the volume of 1 mol of any gas?

22.4 L

What is the ionic charge on the chromium ion in the ionic compound Cr2O3?

3 +

When an aluminum atom loses its valence electrons, what is the charge on the resulting ion?

3+

Krypton is used to increase the efficiency and brightness of flashlight bulbs and electronic flash in photography. Find the number of moles in 0.800 L of krypton gas at STP.

3.57 × 10-2 mol Kr

The configuration for the outermost energy level in Calcium (Ca) is

4s2.

How many valence electrons does an atom of any element in Group 6A have?

6

Nitrogen is an atom with an atomic number of 7 and an atomic mass of 14. Nitrogen is neutral when it has

7 electrons

What is the electron dot structure for ammonia (NH3)?

A (Can't put in image)

What conversion factors can be used to convert molecules of water to grams of water?

A (No image)

A compound has the empirical formula C2H3O and a gram formula mass of 172 g. What is its molecular formula?

C8H12O4

What is the formula for carbon tetrachloride?

CCl4

The least electronegative element from among the following is

Cs

What is the electron dot structure for hydrogen peroxide (H2O2)?

D (Can't put in image)

The covalent molecule among the following is

NH3.

Which compound name ends in a suffix other then -ate?

NH4Cl

Among the following, which combination would be most likely to form an ionic compound?

Na and I

Copper (Cu) has atomic number 29 and an average atomic mass of 63.546. Silver (Ag) has atomic number 47. Which of the following is most likely true of silver?

Silver has an atomic mass greater than 64.

Atomic size generally

decreases as you move from left to right across a period.

When intermolecular and intramolecular bonds are ranked from weakest to strongest, the correct order is

dispersion, dipole-dipole, hydrogen, covalent.

An electron dot diagram is one model of atomic structure. In an electron dot diagram, lithium and sodium are each shown with one dot representing a single valence electron. Although the two elements are very similar, they do not react with other elements in exactly the same way. Why does the electron dot diagram not indicate the differences?

The model does not show all the properties of chemical bonds.

The chemical symbol for an isotope is shown. Which of the following is NOT true?

There are 22 electrons in a neutral atom of the isotope.

Which of the following is NOT a correct interpretation of CH2O, the formula of the compound formaldehyde?

There are two grams of hydrogen for each gram of carbon in this compound.

Substances with similar molar masses often have similar boiling points. Why is the boiling point of water so much higher than the other three substances in the table?

Water molecules have strong intermolecular attraction.

Which element has the greatest electronegativity value?

fluorine

Which of the following correctly shows the number of electrons the element would lose in forming an ionic bond?

gallium, 3

Which group of metals is so reactive that its members are never found uncombined in nature?

alkali metals

Which of the following would you expect to find in a salt composed of aluminum and fluorine?

alternating positive aluminum ions and negative fluorine ions

Network solids

are extremely hard.

The electron dot structure of water (H2O) is shown below.

bent

Which of these elements is a halogen?

bromine