GEN CHEM 1 - ASSIGN 4- CH 3

What is the maximum mass, in grams, of NH3NH3 that can be produced by the reaction of 1.0 g of N2N2 and 1.0 g of H2H2 using the reaction below? N2+H2→NH3N2+H2→NH3 (not balanced)

1.2 g

How many oxygen atoms are there in 52.06 g of carbon dioxide?

1.424 X 10 ^24 CO2 mass/molar mass 52.06 g CO2/ 44 g/ mol = 1.183 1.183 x 6.02 x 10^23 = 7.12 x 10^23 7.12 x 10^23 x 2 = 1.424 x 10^24

How many sulfur atoms are in 1.10 mol of aluminum sulfide? Express the number of atoms of S.

1.99 x 10^24 atoms of sulfur 1.10 mol of aluminum sulfide (Al2S3) yields 3.30 mol of sulfur. Using Avogadro's number, there are 1.99×10^24 atoms of sulfur contained in 1.10 mol of aluminum sulfide.

What is the correct formula weight of iron(III) hydroxide?

106.9 amu Fe(OH)3 55.845 + (3)16 +(3) 1.01 = 106.9

When 5.00 g of methane, CH4, reacts with an excess of oxygen in a combustion reaction, what quantity of H2O is produced?

11.2 g CH4 + 2O2 --> CO2 + 2H2O C-12 H- 1.01 X 4 = 4.04 CH4 = mass (g) / molar mass (g/mol) 5.00g/ 16.04 = 0.311 mol CH4 0.311 mol CH4 x 2/ 1 mol CH4 = 0.622 mol H2O 0..622 mol H2O X 18 = 11.2g

In the balanced chemical equation for this reaction, what is the coefficient in front of the product if the coefficient in front of Cl2(l) is 1?

2 2 K(s) + Cl2 (I) --> 2KCl (s)

How many sulfur atoms are in 0.45 molmol BaSO4BaSO4? Express the number of atoms of S.

2.71 x 10^23 0.45 mol BaSO4 x 6.02 x 10 ^23 atoms = 2.71 x 10^23

A compound whose empirical formula is XF3 consists of 20 % F by mass. What is the atomic mass of X? Express your answer in grams per mole to two significant figures.

230 g/mol

The unbalanced equation for the reaction between methane and bromine is: ___CH4 (g) + __Br2 (I) --> __CBr4 (s) + __HBr (g) Once this equation is balanced what is the value of the coefficient in front of bromine Br2Br2?

4

What is the percentage of oxygen, by mass, in calcium phosphate?

41.3% Ca3(PO4)2 Ca-40.078 x 3 = 120.234 P- 30.974 x 2 = 61.948 O- 8 x 16 = 120.234 8 x 16 / 310.182 = 41.3 %

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO (s) + H2O (l) → Ca(OH)2 (s) In a particular experiment, a 3.50-g sample of CaO is reacted with excess water and 4.12 g of Ca(OH)2 is recovered. What is the percent yield in this experiment?

89.2 %

What units would you assign to "molar mass" in this diagram?

mol/g g/mol

Is the product a solid, liquid, or gas at room temperature?

solid

Lithium and nitrogen react to produce lithium nitride: 6Li (s) + N2 (g) → 2Li3N (s) How many moles of N2 are needed to react with 0.750 mol of lithium?

0.125 0.750 mol Li x 1 mol N2 = 0.750 0.750/6 = 0.125

Which of the following are combustion reactions? 1) CH4 (g) + O2 (g) → CO2 (g) + H2O (l) 2) CaO (s) + CO2 (g) →CaCO3 (s) 3) PbCO3 (s) → PbO (s) + CO2 (g) 4) CH3OH (l) + O2 (g) →CO2 (g) + H2O (l)

1 and 4 -Combustion rxns have CO2 and H2O

Cyclohexane, a commonly used organic solvent, is 85.6%% C and 14.4%% H by mass with a molar mass of 84.2 g/mol. What is its molecular formula?

C6H12 85.6 X 1 / 12.0 = 7.13/7.13 = 1 14.4 X 1 / 1.01= 14.25 / 7.13 = 2 CH2 12 (1) + 1.01 (2) = 14.02 84.2 g/ mol /14.02 = 6 C = 1(6)= 6 H = 2 (6) = 12 multiply by 6 C6H12

A compound that is composed of only carbon and hydrogen contains 80.0% C and 20.0% H by mass. What is the empirical formula of the compound?

CH3 C-80.0% H-20.0% C- 80.0 x 1 /12.0 = 6.66 H- 20.0 x 1/ 1.01 = 19.80 divide by smallest # 6.66/6.66= 1 19.80/6.66= 3 CH3

Which of the following is the correct formula weight for calcium phosphate?

Ca3(PO4)2 =310.2 amu

Which of the following reactions can be classified as a combination reaction? 2C2H2(g)+5O2(g)→4CO2(g)+2H2O(g) 4NH4ClO4(s)→4HCl(g)+2N2(g)+5O2(g)+6H2O(g) 2Mn3O4(s)→6MnO(s)+O2(g) HCl(g)+NH3(g)→NH4Cl(s)

HCl(g)+NH3(g)→NH4Cl(s) Combination rxn: A + B --> AB

When the metallic element potassium combines with the nonmetallic element chlorine, Cl2(l), what is the chemical formula of the product?

KCl K has a 1+ charge Cl has a 1- charge

When Na and S undergo a combination reaction, what is the chemical formula of the product?

Na2S

Pentacarbonyliron(0) (Fe(CO)5)(Fe(CO)5) reacts with phosphorous trifluoride (PF3)(PF3) and hydrogen, releasing carbon monoxide: Fe(CO)5+2PF3+H2→Fe(CO)2(PF3)2(H)2+3COFe(CO)5+2PF3+H2→Fe(CO)2(PF3)2(H)2+3CO If 6.0 g of Fe(CO)5Fe(CO)5 reacts with 4.0 g of PF3PF3 and 4.0 g of H2H2, which is the limiting reagent?

PF3

What units would you assign to "Avogadro's number" in this diagram?

formula units/mol mol/ formula units