Chemistry 103 Exam #1

Write the formula for Ammonium Sulfide

(NH4)2S

Give Examples of Ionic Compounds

(metal and nonmetal) CaF2 BaS K3P BeCl2 Ra3P2

What is the charge of OH and the name?

-1 Hydroxide

What is the charge of NO3 and the name?

-1 Nitrate

What is the charge of CO3 and the name

-2 Carbonate

How many moles of carbon dioxide are present in 6.83 g CO2?

0.155 mol

Calculate the atomic mass of an element if 60.4% of the atoms have a mass of 68.9257 amu and the rest have a mass of 70.9249 amu. Identify the element in the periodic table.

0.604 x 68.9257 = 41.6 0.396 x 70.9249 = 28.1 Element = Ga

Calculate the number of moles in 40.0 g of carbon monoxide

1.43 moles

In 3 moles of O2 how many O2 molecules are there?

1.8 EE24 O2 molecules

Write the symbol for an atom of the element that has 53 protons and 74 neutrons, and is uncharged (neutral).

127^I

What is the molar mass of AlCl3?

133.3g

How many moles are in 8.73 x 1025 atoms of boron?

145 mol

What is the molar mass of AgNO3?

169.9

Complete the following equation and write it in complete and net ionic forms. cobalt(III)bromide + potassium sulfide --->???

2 CoBr3 (aq) + 3 K2S(aq) ---> Co2S3 (s) + 6 KBr (aq) Complete: 2 Co3+ (aq) + 6 Br ̄ (aq) + 6 K+ (aq) + 3 S2- (aq) ---> Co2S3 (s) + 6 K+ (aq) + 6 Br ̄ (aq) Net: 2 Co3+ (aq) + 3 S2- (aq) ---> Co2S3 (s)

Write the net ionic equation for: 2 Na3PO4 + 3 Pb(NO3)2 Pb3(PO4)2 + 6 NaNO3

2 PO4-3(aq) + 3 Pb+2(aq) ---> Pb3(PO4)2 (s)

Complete the following equation and write it in complete and net ionic forms. rubidium fluoride + copper(II)sulfate ---> ???

2 RbF (aq) + CuSO4 (aq) Rb2SO4 (aq) + CuF2 (aq) Complete: 2 Rb+(aq) + 2 F ̄ (aq) + Cu2+ (aq) + SO42- (aq) ---> 2 Rb+ (aq) + SO42- (aq) + Cu2+ (aq) + 2 F ̄ (aq) Net: No Reaction

What is the molar mass of a Ca(SO3)2?

200.2 grams

Magnesium occurs in nature in three isotopic forms: 24Mg (78.70% abundance) = 23.985 amu 26Mg (11.17% abundance) = 25.983 amu 25Mg (10.13% abundance) = 24.986 Calculate Atomic Mass

24.31 amu

How many grams are in 1.25 moles of neon?

25g

How many protons, neutrons, and electrons are in an atom of 56Fe with a charge of +3?

26 protons, 30 neutrons, 23 electrons

What is the molar mass of AlBr3?

266.7g

How many carbon atoms are there in 40.0 g?

2EE24 atoms

Calculate the number of moles in 40.0 g of carbon

3.33 moles

How many grams of Al are in .150 grams of Al?

4.05 grams

Write the complete ionic equation for: 2 Na3PO4 + 3 Pb(NO3)2 Pb3(PO4)2 + 6 NaNO3

6 Na+(aq) + 2 PO4-3(aq) + 3 Pb+2(aq) + 6 NO3+ (aq) ---> Pb3(PO4)2 (s) + 6 Na+(aq) + 6 NO3+ (aq)

What is avogadro's number?

6.022EE23

Calculate the atomic mass and name the element 69.17% abundance and 62.9295898 amu 30.83% abundance and 64.9277029 amu

63.55 amu Element = Cu

How many atoms are there in .150 moles of Al?

9.03EE22 atoms

How many moles are there in 5.666EE24 atoms of Na?

9.409 moles

Write the Ionic Formula for Aluminum and Hydroxide

Al(OH)3

Which polyatomic ion is positively charged and what is it charged?

Ammonium NH4+

What is (NH4)2(CO3) called?

Ammonium Carbonate

Calculate the AMU 69Ga has an abundance of 60.108% and amu of 68.925580 71Ga has an abundance of 39.892% and amu of 70.947005

Amu = 69.73

A sample of an oxide of arsenic is found to contain 75.74% arsenic. What is its empirical formula?

As2O3

What is the atomic number, mass number and symbol for the element that has 45 protons and 58 neutrons?

Atomic Number = 45 Mass = 103 Symbol = Rh

Write the formula for Barium Hydroxide

Ba(OH)2

What is the empirical formula for a compound containing 38.8% carbon, 16.2% hydrogen and 45.1% nitrogen?

CH5N

Write the formula for Calcium Phosphate

Ca3(PO4)2

What is the empirical formula compound that contains 51.33% calcium and 48.66% fluoride?

CaF2

Which polyatomic ions has a charge of -2?

Carbonate - CO3 Sulfate - SO4

Write the Complete and Net Ionic Equations for: chromium(III)nitrate(aq) + iron(II)sulfate(aq) -- ->chromium(III)sulfate(aq) + iron(II)nitrate(aq)

Complete: 2 Cr3+ (aq) + 6 NO3 ̄ (aq) + 3 Fe2+ (aq) + 3 SO42- (aq) ---> 2 Cr3+ (aq) + 6 NO3 ̄ (aq) + 3 Fe2+ (aq) + 3 SO42- (aq) Net: No reaction

Write Complete and Net Ionic Equations for: AgNO3(aq) + KCl(aq) AgCl(s) + KNO3(aq)

Complete: Ag+ (aq) + NO3 ̄ (aq) + K+ (aq) + Cl ̄ (aq) ---> AgCl (s) + K+ (aq) + NO3 ̄ (aq) Net: Ag+ (aq) + Cl ̄ (aq) ---> AgCl (s)

Write the Complete and Net Ionic Equations for: MnCl2 (aq) + (NH4)2CO3 (aq) ---> MnCO3 (s) + 2 NH4Cl (aq)

Complete: Mn2+ (aq) + 2 Cl ̄ (aq) + 2 NH4+ (aq) + CO32- (aq) ---> MnCO3 (s) + 2 NH4+ (aq) + 2 Cl ̄ (aq) Net: Mn2+ (aq) + CO32- (aq) ---> MnCO3 (s)

Write examples of covalent compounds

H2O CO2 Cl2 Br2 H2 I2

Complete the following equation and write it in complete and net ionic forms. K3PO4(aq) + Al(NO3)3(aq) ---> ???

K3PO4 (aq) + Al(NO3)3 (aq) AlPO4 (s) + 3 KNO3 (aq) Complete: 3 K+ (aq) + PO43- (aq) + Al3+ (aq) + 3 NO3 ̄ (aq) ---> AlPO4 (s) + 3 K+ (aq) + 3 NO3 ̄ (aq) Net: Al3+ (aq) + PO43- (aq) ---> AlPO4 (s)

Write the Ionic Formula for Lithium and Sulfur

Li2S

Write the Ionic Formula for Magnesium Bromide

MgBr2

A compound is found to contain 23.3% magnesium, 30.7% sulfur and 46.0% oxygen. What is the empirical formula of this compound?

MgSO3

Which of the following combinations will likely result in a precipitation product? Mixing a (NH4)2SO4 solution with a MgCl2 solution Mixing a BaCl2 solution with a KOH solution Mixing a Mg(NO3)2 solution with a NaF solution Mixing a Pb(NO3)2 solution with a LiClO4 solution

Mixing a Mg(NO3)2 solution with a NaF solution

What is the empirical formula compound that contains 63.64 % nitrogen and 36.36% oxygen by mass?

N2O

A sample of an oxide of nitrogen is found to contain 30.4% nitrogen. What is its empirical formula?

NO2

Write the Ionic Formula for Sodium and Chloride

NaCl

What is the formula for phosphate and its charge?

PO4 -3

What is the empirical formula of a compound containing 60.0% sulfur and 40.0% oxygen by mass?

SO3

What is the formula for sulphate and its charge?

SO4 -2

What is the empirical formula compound that contains 25.2504% Ti and 74.7496% Cl?

TiCl4

Natural samples of copper contain two isotopes. 63Cu has a mass of 62.930 amu and 65Cu has a mass of 64.928 amu. The percent abundance of 63Cu is 69.09%. Calculate the atomic mass of copper.

hint :% abundance 65Cu: 100.00% - 69.09% = 30.91%