INTRO CHEM FINAL

Calculate the oxidation number of the chlorine in perchloric acid, HClO4

+7

In the ionic compound with the general formula M2X3 the likely charge of X is

-2

How many valence electrons will lithium ion have?

0

Orbit three in the Bohr model

0

The formal charges on Cl and O i the structure shown for the ClO- ion are, respectively

0 and -1

Calculate the number of moles of HCl in 62.85 mL of 0.452 M hydrochloric acid

0.0285 mol

Calculate the number of moles of HCl in 62.85 mL of 0.453 M hydrochloric acid

0.0285 mol

How many moles of molecules are in 10.0 g of aspartame? (C14H18N2O5)

0.0340 mols

When 2.61 g of solid Na2CO3 is dosssolved in sufficient water to make 250. mL of solution, the concentration of Na2CO3 is:

0.0985 M

How many moles are in 38.7 g of PCl5 (phosphorus pentachloride)

0.186 mol

Calculate the mass of solute needed to prepare 1.575 L of 0.00250 M NaClO3 (molar mass= 106.45g/mol)

0.419 g

Lewis Structure Rules

1. total valence electrons they have 2. total valence electrons they want 3. subtract 4. divide by 2 that's the number of bonds

How many molecules are in 0.00500 grams of C14H18N2O5

1.02 x 10^19

13.053- 2.07 =

10.98

Magnesium fluoride is used in the ceramics and glass industry. What is the mass of 1.72 mole of magnesium fluoride

107 g

3.295/0.020 =

160

Orbit one in the Bohr model

2

The number of hydrogen atoms in 0.050 mol of C3H8O3 is

2.4 x 10^23 H atoms

Calculate the atomic mass of the element magnesium from its stable isotopes listed below and report the value to the 3 sig. figs., no unit 24Mg, 23.985 amu, 79.0% 25Mg, 24.986 amu, 10.0% 26Mg, 25,983 amu, 11.0%

24.3

What is the molar mass of C14H18N2O5 (aspartame)

294 g/mol

How many valence electrons will aluminum have?

3

In carbon disulfide, how many unshared pairs of electrons are on each sulfur atom?

3

321.5 cm3 to mm3

3.215 x 10^5

what is Aluminum sulfate, Al2(SO4)3 molar mass

342.15 g/mol

42.6x(12.2-3.10)

390

What is the net ionic equation for 3Co2+(aq)+6NO3(aq)+6NO3(aq)+6Na+(aq)+(2PO4)3-(aq)---> Co3(PO4)2(s)+6Na+(aq)+6NO3(aq)

3Co2+(aq)+2(PO4)3-(aq) ---.> Co3(PO4)2(s)

4.01 milligrams to kilograms

4.01 x 10^-6

Aluminum will react with bromine to form aluminum bromide Al(s)+Br2(l)---> Al2Br6(s) [unbalanced] How many moles of Al are needed to form 2.43 mol of Al2Br6

4.86 mol

How many atoms of nitrogen are in 1.20 grams of C14H18N2O5?

4.91 x 10^23

Calculate the number of oxygen atoms in 29.34 g of sodium sulfate

4.976 x 10^23

What is the mass in grams of 1.56 moles of C14H18N2O5?

459 g

What is the mass in grams of 8.35 x 10^22 molecules of CBr4

46.0 g

How many valence electrons will Sulfur have?

6

ionic bond vs covalent bond

Ionic- transfer of electrons Covalent- sharing of electrons

"Plum Pudding" Model with positive charged embedded in negative matrix

J.J Thomson

Atoms as discrete units, developed four postulates

John Dalton

Select the precipitate that forms when the following reactants are mixed Mg(Ch3Coo)2(aq)+LiOH(aq)-->

Mg(OH)2

Which of the following compounds is ionic?

MgCl2

2MnO2(s)+KClO3(aq)+2KOH(aq)-->2KMnO4(aq)+KCl(aq)+H2O(l)

Mn in MnO2 is oxidized

Which one of the following combinations of names and formulas of ions is incorrect?

NO-2 Nitrate

what are the ions of MgCO3. When sodium carbonate and magnesium chloride are combined

Na+ and Cl-

Which one of the following ionic compounds is soluble in water?

Na2S

Balance Na(s)+SF6(g)---> Na2S(s)+NaF(s)

Na= 8 Sf6=1 Na2S=1 NaF=6

Described circular orbits for electrons

Niels Bohr

Arrange oxygen, sulfur, calcium, rubidium, and potassium in order of decreasing electronegativity

O>S>Ca>K>Rb

How does oxygen form?

Oxygen forms ionic and covalent compounds Has same number of protons, neutrons, and electrons

Balance PbS(s)+PbSO4(s)---> Pb(s)+SO2(g)

PbS=1 PbSO4=1 Pb=2 So2=2

BaCl2(aq)+K2SO4(aq)--->BaSO4(s)+2KCl(aq)

Precipitation

Select the classification for the following reaction Fe(s)+2Fe3+(aq)---->3Fe2+(aq)

Redox

In which one of the following species is the central atom an exception to the octet rule?

SF6

A weak acid

When dissolved in water, they do not ionize completely

Which of the following is a weak acid?

HF

What is the molecular symmetry around the carbons in the CCl2CH2 as predicted by the VSEPR theory?

trigonal planar

pure compound

two or more atoms joined together

How many valence electrons will Fluoride have

8

Orbit two in the Bohr model

8

What is the mass of lead in 139 g of Pb(NO3)2 (Lead (II) nitrate)

87.0 g

Covalent bond

A chemical bond that involves sharing a pair of electrons between atoms in a molecule

What is the AXE designation of PCl3

AX3E

In a Lewis structure for a molecule or ion, the formal charges on the atoms:

Add up to the charge on the molecule or ion

Use VSEPR theory to decide which one of the following ions and molecules is likely to be planar.

BF3

Which is a nonmetal

Bromine, Br, Z=35

Find the empirical formula of a compound that is 54.5% C, 9.15% H, and 36.3% O

C2H4O

Find the molecular formula of a compound that is 54.5% C, 9.15% H, and 36.3% O (molecular molar mass of 132.15g)

C6H12O3

C6H12O6(s)+O2(g)---> CO2(g)+H2O(l)

C6H12O6= 1 O2=6 Co2=6 H2O=6

Isomers of CH3CH2CH2OH

CH3CH2OCH3 CH3OCH2CH3 OHCH2CH2CH3

Formula for the compound Calcium and Chlorine

CaCl2

After an atom has lost an electron it becomes a/an blank and has a blank charge

Cation, positive

One mole of O2 has a mass of 16.0 g

False

One mole of methane (CH4) contains a total of 3 x 10^24

False

ionic bond

Formed when one or more electrons are transferred from one atom to another

Which one of the following substances is the best electrolyte

HCl

uncertainty

an estimate of how much a measured or calculated value differs from a true value

What is the molecular shape of NO2- as predicted by the VSEPR theory

bent

Example of chemical change

burning wood

The substance, CoCl2, is useful as a humidity indicator because it changes from pale blue to pink as it gains water from moist air. What is its name?

cobalt(II) chloride

Gas to liquid

condensation and is exothermic

In a correctly balanced equation, the number of reactant molecules must equal the number of product molecules

false

Liquid to solid

freezing (exothermic)

What type of isomer is C2H2Cl2

geometric

Total number of protons and neutrons in a atom

mass number

pure element

only one type of atom present

What is the name of the acid formed when HClO4 liquid is dissolved in water?

perchloric acid

What is the name of PCl3?

phosphorus trichloride

IS the molecule PCl3 polar or nonpolar?

polar

What is the direction of the polar PCl3

straight down

What type of the isomer is C3H8O

structural

Solid to gas

sublimation, endothermic

According to VSEPR theory, a molecule with the general formula AX3 will have a blank molecular shape

trigonal planar