Chem 1153 Final UMD

Which one of the following statements is correct?

The composition is uniform throughout a homogenous mixture

Which one of the following substances is classified as an element?

P4

A(n)________ is a pure substance that is composed of only one type of atom

element

The density of liquid mercury is 13.5 g/cm3. What mass of mercury will fill a 12oz soda can?

4.80 x 10^3

How many protons, neutrons, and electrons are in a yttrium-89 atom?

39 protons, 50 neutrons, 39 electrons

What is the atomic symbol for an element with 38 protons and 50 neutrons?

88top 38 bottom Sr

Two isotopes of a given element will have the same number of ____, but a different number of ______ in their nucleus?

protons, neutrons

All of the following are examples of intrusive properties except for

mass

What is the correct answer to the following expression: (53+63)x0.17051?

19.8

a covalent bond results when ______

electrons are shared between a pair of atoms

What is the correct name for PbO2?

Lead (IV) Oxide

what is the correct formula for hypochlorous acid?

HClO

The formula for calcium dichromate is Ca(Cr2O7). what is the formula for aluminum dichromate?

Al2(Cr2O7)3

Which one of the following has a bonding capacity of 3?

P

How many valence electrons are in the Lewis structure for BrO- ?

14

One reason electronegativity increases from left to right across a period is______

an increase in the number of protons in nucleus

Which one of the following bonds is the weakest?

C-C

the lattice energy for ionic crystals increases (becomes more negative) as the charge on the ions________ and the size of the ions ________

increases, decreases

Dispersion forces are due to _______

temporary dipoles

a dipole dipole interaction is an intermolecular force that occurs between

two polar molecules

identify the polar molecule

CHCl3

When two liquids mix completely in all proportions, they are ______

miscible

based on their boiling points, which of the following compounds has the largest dipole dipole interaction?

acetonitrile, CH3CN

a hydration sphere forms around an ion in aqueous solution due to

ion dipole interactions

what is the theoretical yield of phosphoric acid ( H3PO4, 98.0 g/mol) when 10.0 g P4O10 (284 g/mol) reacts with excess water (18.02 g/mol)?

13.8 g

What volume of 2.50 M NaOH (40.00 g/mol) contains 0.100 mole of NaOH

40.0 mL

How many grams of solid potassium chlorate (KClO3, 122.55 g/mol) are needed to make 150 mL of 0.50 M solution?

9.2 g

What volume of 12.0 M HCl solution needs to be diluted to produce 500.0 mL of 3.00 M HCl solution?

0.125 L

If 5.15 g Fe(NO3)3 is dissolved in enough water to make exactly 150.00 mL of solution, what is the molar concentration of nitrate ion? (Fe(NO3)3=241.86 g/mol)

0.426 M

Which of the following would behave as a strong electrolyte in water?

Table salt, NaCl

Which of the following compounds is a weak acid?

CH3CO2H

Which of the following ionic compounds is insoluble in water?

Cu3(PO4)2

What is the formula of the precipitate that forms when aqueous ammonium phosphate and aqueous copper (II) Chloride are mixed?

Cu3(PO4)2

what is the oxidation of sulfur in the thiosulfate ion (S2)32-)?

+2

Which of the following is the greatest length?

5.0 x 10^6 nm

The nucleus of an atom

Does not account for a large amount of the total volume of an atom

a pure substance composed of two or more different elements is

a chemical compound

Which one of the following regions of the electromagnetic spectrum has the longest wavelength?

infrared

when heated in a flame, sodium atoms emit light. with a frequency of 5.09x10^14 s^-1. What is the wavelength of this radiation?

589 nm

What is the energy in kJ of 1.00 mole of green light with a wavelength of 507 nm?

236 kJ

for which of the following transitions would a hydrogen atom absorb a photon with the longest wavelength?

n=5 to n=6

All of the following sets of quantum numbers are allowed except

n=6 l=2 m=+3

which of the following is associated with the value of the l quantum number?

the shape of an orbital

what type of orbital is designated n=4 l=0 m=0

4s

which one of the following sets refers to a 4d orbital?

n=4 l=2 m=-1

what is the orbital designation for an electron with the quantum numbers n=3 l=2

3d

Which of the following statements is false

Larger ions typically form stronger ionic bonds than smaller ions

How many valence electrons are contained in the Lewis structure of CO plus

9

How do you drink and have at most ______ electrons and it's valence shell

2

Which combination of Atoms is most likely produce a compound with ionic bonds

Al and Br

Which one of the ionic compounds below what do you expect to have the largest lattice energy

BeO

A selenium atom has _____ valence electrons

6

In VSEPR theory molecular geometry is determined by

electron-electron repulsive forces

How many lone pairs of electrons are assigned to the sulfur atom in H2S

2

The central atom in PH3 is surrounded by

Three single bonds and one lone pair of electrons

Use VSEPR theory to predict the molecular geometry of BrF5

Square pyramidal

Which of the following compounds has polar covalent bonds: NaBr, Br2, HBr, and CBr4?

HBr and CBr4

Electronegativity is a measure of

The ability of an Atom and a molecule to attract electrons to itself

What are the bond angles in a molecule with a tetrahedral molecular geometry

109.5°

Which one of the following molecules is polar

S02

Use Lewis structures to predict the bond order for a carbon oxygen bond in carbonate ion

4/3

To form a molecule with trigonal pyramidal electron geometry what set of pure atomic orbitals must be mixed

One s three p and one d

What is the hybridization of the nitrogen atom in NCl3

sp^3

What is the molecular geometry around a central Atom that is sp^3 hybridized and has two lone pairs of electrons

Bent

Dispersion forces are due to

temporary dipoles

Which molecule below exhibits the greatest dispersion forces

CH3CH2CH2CH3

Hydration sphere forms around an ion in aqueous solution due to

Ion - dipole interactions

For a molecule to exhibit dipole - dipole interactions it must

have a permanent dipole moment

Which compound below will exhibit hydrogen bonding with itself in the liquid state

CH3CH2NH2

Hydrophilic substances

Are soluble in water

Molarity, M, is defined as

moles of solute dissolved in 1 L of solution

If 120 G of NaOH (40.00G/MOL') are used to prepare 500.0 mL of solution, what would the concentration be

6.0 M

In the dilution of 10.0 mL of a . 10M solution of HCl to a volume of 20.0 ML what remains unchanged

The moles of HCl in the solution

If the molar concentration of sodium phosphate is 0.30 M what is the concentration of sodium ions

0.90 M

The energy stored in chemical bonds is a form of

potential energy

If a chemical reaction causes the temperature of the reaction vessel to decrease it is a _____ reaction

Endothermic

During an exothermic process ________ for the system

Delta H < than 0

How much energy is needed to change the temperature of 25.00 mL of water from 10.0°C to 95.0°C

8.89 kJ

In addition to identifying the reactants and products of thermochemical reaction equation provides

The amount of energy released or absorbed

The mass of 0.25 mol of an element is 8.0 g what is the element

O2