Chemistry 111 #3

What is the mass of a single bromine molecule, Br2?

79.904Br2+79.905Br=159.808*1atom/6.02*10^23=2.654*10^-22

Octa

8

nona

9

Write the formula for barium nitride.

Ba3N2

Hepta

7

Calculate the mass percent composition of lithium in Li3PO4. *30.72 % *26.75 % *55.27 % *17.98 % *20.82 %

%Li=3(li)/m(li3Po4)*100%=3.69g/mole/115.8g/mole*100%=17.9

The fuel used in many disposable lighters is liquid butane, C4H10. How many carbon atoms are in 3.50 g of butane?

0.06024 mol C4H10 x (6.022x10^23 molecules C4H10)/(1 mol C4H10) = 3.627x10^22 molecules C4H10 And there are 4 carbon atoms in 1 molecule of butane, so use the following ratio: 3.627 x 10^22 molecules C4H10 x (4 atoms C)/(1 molecule C4H10) = 1.45 x 10^23 atoms of carbon are present

Mono

1

Mg(NO2)2 2 magnesium atoms, 2 nitrogen atoms and 4 oxygen atoms. 1 magnesium atom, 2 nitrogen atoms and 2 oxygen atoms. 1 magnesium atom, 4 nitrogen atoms and 4 oxygen atoms. 1 magnesium atom, 2 nitrogen atoms and 4 oxygen atoms.

1 magnesium atom, 2 nitrogen atoms and 4 oxygen atoms.

Hemi

1/2

deca

10

How many moles of C and H?

158.652g*1mole/12.011g=13.2]08=13.2moles 21.348*1mole/1.0079g=21.1]8=21.2moles

Di

2

Fe2O3 3 iron atoms and 2 oxygen atoms. 2 iron atoms and 3 oxygen atoms. 2 iron atoms and 6 oxygen atoms. 1 iron atom and 1 oxygen atom.

2 iron atoms and 3 oxygen atoms.

Li2SO4 1 lithium atom, 1 sulfur atom and 4 oxygen atoms. 2 lithium atoms, 1 sulfur atom and 4 oxygen atoms. 2 lithium atoms, 4 sulfur atoms and 4 oxygen atoms. 2 lithium atoms, 2 sulfur atoms and 8 oxygen atoms.

2 lithium atoms, 1 sulfur atom, and 4 oxygen atoms.

Tri

3

The chloride of an unknown metal is believed to have the formula MCl3. A 1.95 g sample of the compound is found to contain 3.606×10−2molCl. Find the atomic mass of M.

3.606*10^-2molescl*1mol m/3 molescl=0.01202g/ml mT=mM+mC 3.606*10^-2 molcl*35.4539cl/1molecl=1.278456g/cl mT=1.95 mC=1.278456 1.95-1.278456=0.671544g/m 0.671544g/ml/0.01202g/ml=55.868 iron=56g/ml

Tetra

4

What is the mass of 0.500 mol of carbon tetrafluoride, CF4? 176 g 44.0 g 88.0 g 5.68 × 10-3 g

44.0

Penta

5

Hexa

6

Which of the following contains BOTH ionic and covalent bonds? *BaSO4 *CaI2 *SF6 COS None of the above contain both ionic and covalent bonds.

BaSo4

How many grams of C and H are there in a 180.0 g sample of this substance?

C-88% 180.0g*0.8814=158.6]52=158.7g H-11.86% 180.0g*0.1186=21.34]8=21.35g mC, mH= 158.7,21.3g

What is the empirical formula of the compound with the molecular formula C12H8? C2H2 C10H9 C3H2 C6H4

C3H2

The molar mass is determined to be 136.26 g/mol. What is the molecular formula?

C5n,H8n 5(12.011)+8(1.0079)=68.1182 then you divide 136.26 by 68.1182=2 then multiply 2*5=10, 2*8=16 C10H16

Carbon terachloride

CCL4

CaF2

Calcium Fluoride

Ca(OH)2

Calcium hydroxide

How many molecules of butane are contained in 25.0 mL of butane? The density of butane is 0.6011 g/mL and the molar mass is 58.12 g/mol.

Calculate the mass of 25.0 ml of butane, since the density is provide, it is easily calculated as 15.0 grams. In order to calculate the amount of moles, simply divide 15.0 grams by the molar mass and you will get 0.258 moles. Multiply that by Avogadro's number (6.02 * 10^23) and you will get 1.55 * 10^23 molecules.

What is the empirical formula?

CnHm C13.2/13.2 Divide by lowest number H21.2/13.2 C1,H1.6 Then you have to multiply until you get a whole number and since 1.6 isn't a whole number you have to multiply 1-through whatever number get a whole number so when you multiply 1.6*5 you get 8 then you do. C5H8

Coso4*7H2O

Cobalt (II) Sulfate heptahydrate

CuOH

Copper(I) hydroxide

Carbon tetrafluoride (Cf4) is used as a low-temperature refrigerant in refrigerators. What type of bonding occurs between the atoms of a molecule? covalent metallic ionic

Covalent

What is the chemical formula for chromium(III) sulfate?

Cr2(so4)3

What is the empirical formula for C10H20O5 ? *C2H4O *C2H5O *CH2O *CHO *CHO2

Divide by 5 C2H4O

How many moles of NF3 contain 2.55 × 1024 fluorine atoms? *7.87 moles NF3 *4.23 moles NF3 *2.82 moles NF3 *1.41 moles NF3 *12.7 moles NF3

First need to get moles of Cl/Avogadro's number 2.55*10^24/6.022*10^23=4.23 moles 3CL atoms Cl/3 4.23/3 1.41 moles

Identify the compound with covalent bonding. *NaCl *K *H2O *He *S

H20

Choose a structural formula for hydrogen telluride. H−Te H−H H−Te−H H2Te

H−Te−H

IrBr3 *4H2O

Iridium (III) bromide tetrahydrate

FeSo4

Iron (II) Sulfate

Identify the compound with ionic bonds. *H2 *Ne *KCl *H2O *CO

KCl

Molecular copounds

Molecular compounds are made up of two non-metals

KI

Potassium iodine

K2O

Potassium oxide

Decasulfur

S10O

Sulfur hexafluoride

SF6

Silicon Oxide

SiO

NaHco3

Sodium Bicarbonate

NaoH

Sodium Hydroxide

Na2So4

Sodium Sulfate

What is the chemical formula for strontium hydroxide? SrOH2 SrH2 Sr(OH)2 SrOH

Sr(OH)2

SnCl4

Tin(IV) chloride

VCL

Vanadium(IV)chloride

Calculate the mass of 1.00×10^24 (a septillion) molecules of water.

We know that a mole of water has a mass of 18 grams, and also that a mole contains 6.023 * 10**23 molecules. We are given 1 septillion molecules, which is 1.0 * 10**24 or also 10.0 * 10**23 molecules. Therefore we have 10/6.023 or 1.66 moles of water. Multiply that by the molar mass of water (18 gm.) and we get 29.88 grams mass for 1 septillion molecules of water.

covalent bond

a covalent bond is between 2 nonmetals.

Structural formula

a sketch or diagram of how the atoms in the molecule are bonded to each other.

ionic bond

an ionic bond is between a metal and a nonmetal

Ca(HCo3)2

calcium bicarbonate

Naming Simple Organic Hydrocarbons

chapter 4 pg 46

Type 2 cation

chapter 4 pg30

Common Polyatomic Ions

chapter 4 pg32

Determine the name for N2O5. *nitrogen (II) oxide *nitrogen oxide *nitrogen tetroxide *nitrogen (IV) oxide *dinitrogen pentoxide

dinitrogen pentoxide

What is the chemical name for P2I4? *diphosphorus iodine *phosphorus (IV) iodine *phosphorus tetraiodine *phosphorus (II) iodine *diphosphorus tetraiodide

diphosphorus tetraiodide

Fe2O3 molecular ionic

ionic

NaI *ionic *molecular

ionic

What type of bonding occurs in calcium chloride, CaCl2? covalent metallic ionic

ionic

Write the name for FeS. iron sulfide iron(I) sulfide iron(I) sulfate iron(II) sulfide iron(II) sulfate

iron(II) sulfide

Li2O

lithium oxide

What type of bonding occurs in a sample of pure chromium, ? In other words, how is one chromium atom held to another chromium atom? covalent metallic ionic

metallic

C02 *molecular *ionic

molecular

PCl3 *molecular *ionic

molecular

A flask contains 0.200 molof liquid bromine, Br2. Determine the number of bromine molecules present in the flask.

molecules = 0.200 moles Br2 x 6.022x10^23 molecules/mol = 1.20x10^23 molecules

Pdo2

palladium(II) oxide

KMnO4 1 potassium atom, 4 manganese atoms and 4 oxygen atoms. 4 potassium atoms, 4 manganese atoms and 4 oxygen atoms. 1 potassium atom, 1 manganese atom and 1 oxygen atom. 1 potassium atom, 1 manganese atom and 4 oxygen atoms.

potassium atom, 1 manganese atom and 4 oxygen atoms.

AgOH

silver hydroxide

AgNO3

silver nitrate

Na3PO4

sodium phosphate

Na2S is named sodium sulfide. sodium disulfide. sodium sulfur. sodium(II) sulfide.

sodium sulfide.

Determine the name for P4O10. *diphosphorus pentoxide *tetraphosphorus decoxide *phosphorus (II) oxide *phosphorus (IV) oxide *phosphorus oxide

tetraphosphorus decoxide

Molecular formula

the actual number of atoms of each element in a molecule of a compound. H2O2 C8H16

Empirical formula

the simplest whole-number (ratio) representation of the type and number of elements present in a molecule. (This is what all ionic compounds use) HO CH2

Give the name for SnO. *tin (II) oxide *tin (IV) oxide *tin (I) oxide *tin (III) oxide

tin (II) oxide