Chemistry Test 3

How many covalent bonds will a hydrogen atom normally make? A. 1 B. 2 C. 3 D. 4 E. 5

A. 1

What is the mass percent (m/m) concentration of a solution prepared from 500g NaCl and 2.50kg of water? A. 16.7% B. 0.050% C. 20.0% D. 1.67% E. 0.167%

A. 16.7%

What is the molarity of a solution which contains 58.4g of sodium chloride dissolved in 500 mL of solution? A. 2.00 M B. 0.500 M C. 1.50 M D. 1.00 M E. 4.00 M

A. 2.00 M

A diver exhales a bubble with a volume of 250 mL at a pressure of 2.42 atm and a temp of 15*C. What is the volume of the bubble when it reaches the surface where the pressure is 1.00 atm and the temp is 27*C? A. 630 mL B. 310 mL C. 580 mL D. 110 mL E. 1,100 mL

A. 630 mL

When some of the sugar added to iced tea remains undissolved at the bottom of the glass, the solution is? A. Saturated B. Dilute C. Polar D. Unsaturated E. Nonpolar

A. Saturated

The shape of the polyatomic ammonium ion, NH4+ is __________? A. Tetrahedral B. Trigonal Pyramidal C. Planar D. Linear E. Bent

A. Tetrahedral

How many moles of hydrogen are needed to react with 0.234 mol of oxygen according to this equation? 2H2(g) + 02(g) ---- 2H20(g) A. 2.00 mol B. 0.468 mol C. 0.936 mol D. 0.234 mol E. 0.117 mol

B. 0.468 mol

A 1.00g sample of an unknown gas has a pressure of 35.8mm Hg, a volume of 20.0L and a temp of 25*C. What is the molar mass of the gas? A. 2.18 g/mol B. 26.0 g/mol C. 0.0385 g/mol D. 77.0 g/mol E. 52.0 g/mol

B. 26.0 g/mol

Given the following equation, what is the correct form of the conversion factor needed to convert the number of moles of O2 to the moles of Fe reacted? 4 Fe(s) + 3O2(g) ---- 2Fe2O3(s) A. 2 mol Fe2O3 / 4 mol Fe B. 4 mol Fe / 3 mol O2 C. 4 mol Fe / 2 mol Fe2O3 D. 2 mol Fe2O3 / 3 mol O2 E. 3 mol O2 / 2 mol Fe2O3

B. 4 mol Fe / 3 mol O2

How many mL of 1.24 M H2SO4 reacts with 1.26g of Al 2Al + 3H2SO4 ---- Al2(SO4)3 + 3H2 A. 0.565 mL B. 56.5 mL C. 44.8 mL D. 37.7 mL E. 22.2 mL

B. 56.5 mL

The solubility of KI is 50g in 100g of H2O at 20*C. If 110 grams of KI are added to 200 grams of H2O? A. The solution will start boiling B. A saturated solution will form C. The solution will be unsaturated D. All of the KI will dissolve E. The solution will freeze

B. A saturated solution will form

Which of the following substances contains a non polar bond? A. H20 B. N2 C. NaCl D. MgF2 E. NH3

B. N2

2Mg(s) + O2(g) --> 2MgO(s) How many grams of MgO are produced when 40.0 grams of O2 react completely with Mg? A. 60.8 g B. 50.4 g C. 101 g D. 30.4 g E. 201 g

C. 101 g

When this equation is balanced, what is the best coefficient for water? CH4(g) + O2(g) ---- CO2(g) + 2H2O(g) Balanced Equation= CH4 + 2O2 ---- CO2 + 2H20 A. 0.5 B. 1.5 C. 2 D. 1 E. 3

C. 2

How many covalent bonds will a nitrogen atom normally make? A. 1 B. 2 C. 3 D. 4 E. 6

C. 3

When 50.0 g of acetylene is allowed to react with excess oxygen, 75.0 g of CO2 are formed. What is the percent yield of carbon dioxide? 2C2H2(g) + 5O2(g) ---- 4CO2(g) +2H209(g) A. 150% B. 88.8% C. 44.4% D. 100% E. 6.7%

C. 44.4%

If 20.0 g acetylene is allowed to completely react with oxygen, how many grams of O2 are reacted? 2C2H2(g) + 5O2(g) ---- 4CO2(g) +2H209(g) A. 5.00 g B. 9.85 g C. 61.4 g D. 20.0 g E. 24.6 g

C. 61.4 g

A 2.35g sample of KClO3 is reacted. How many mL of O2 gas is produced at a pressure of 740mm Hg and a temp of 25*C 2KClO3(s) ---- 2KCl(s) + 302(g) A. 482 mL B. 60.7 mL C. 722 mL D. 22.4 mL E. 0.482 mL

C. 722 mL

What unit of temp is used in gas law calculations? A. Celsius B. Fahrenheit C. Kelvin D. either Celsius or Fahrenheit E. either Celsius or Kelvin

C. Kelvin

The molarity of a solution refers to ______? A. Grams of solute/ L of solution B. Grams of solute/ 100mL of solution C. Moles of solute/ L of solution D. Moles of solute/ L of solvent E. Grams of solute/ 100 mL of solution

C. Moles of solute/ L of solution

How many kilojoules are required to warm 15.0 g of water from 75.0*C to 100.0*C and convert it to steam at 100.0*C? A. 1,130 kJ B. 380 kJ C. 848 kJ D. 35.5 kJ E. 975 kJ

D. 35.5 kJ

The strongest forces between HF molecules are ________? A. Dipole-Dipole Attractions B. Nonpolar Covalent Bonds C. Dispersion Forces D. Hydrogen Bonds E. Ionic Bonds

D. Hydrogen Bonds

A solution is prepared by dissolving 2g of KCl in 100g of H2O. In this solution, H2O is the ________? A. Solute B. Ionic Compound C. Solid D. Solvent E. Solution

D. Solvent

a 1.26 sample of He gas has a pressure of 0.123 atm and a volume of 32.6 L. What is the temp of the sample in *C? A. 273*C B. 118*C C. 155*C D. 300*C E. -118*C

E. -118*C

The volume of a gas with a pressure of 1.2 atm increases from 1.0 L to 4.0 L. What is the final pressure of the gas, assuming constant temperature? A. 3.3 atm B. 4.8 atm C. 1.0 atm D. 1.2 atm E. 0.30 atm

E. 0.30 atm

The temp of a 500 mL sample of gas increases from 150K to 350K. what is the final volume of the sample gas, if the pressure in the container is kept constant? A. 0.0095 ML B. 110 mL C. 210 mL D. 0.0047 mL E. 1,170 mL

E. 1,170 mL

If the heat of fusion for water is 334 J/g, how many joules are needed to melt 45.0 g of ice at 0.0* C? A. O J B. 334 J C. 450 J D. 7.42 J E. 1.50 x 10^4 J

E. 1.50 x 10^4 J

At STP conditions, 11.0g of SO2 have a volume of _____? A. 25.0 L B. 130 L C. 22.4 L D. 0.00762 L E. 3.85 L

E. 3.85 L

How many kJ are produced when 50.0 g of oxygen reacts with excess H2(g)? 2H2(g) + O2(g) ---- 2H2O(l) + 572 kJ A. 715 kJ B. 572 kJ C. 1140 kJ D. 446 kJ E. 894 kJ *see calculation sheet

E. 894 kJ

According to the kinetic-molecular theory, particles of a gas? A. Lose their valence electrons B. Are very large particles C. Move Slowly D. Decrease in kinetic energy as temp increases E. Are very far apart

E. Are very far apart

A solution of an electrolyte in water will ______ A. Always contain CO2 B. Be negatively charged C. Be positively charged D. Dissolve in gasoline E. Carry an electric current

E. Carry an electric current

If 16.0 g of methane is allowed to react with 32.0 g of oxygen, what is the limiting reagent/ A. Carbon Dioxide B. Water C. Methane D. Fire E. Oxygen

E. Oxygen

The O-H bond in water is polar because? A. It is a hydrogen bond B. Oxygen occupies more space than hydrogen C. Hydrogen is much more electronegative than oxygen D. It is an ionic bond E. Oxygen is much more electronegative than hydrogen

E. Oxygen is much more electronegative than hydrogen

The shape of the ammonia molecule is _________? A. Square B. Octagonal C. Hexagonal D. Linear E. Trigonal Pyramidal

E. Trigonal Pyramidal