Chem. 1A Exam 1 Practice Problems: This is not a "practice test", these are sample questions that will verify your readiness to take theexam. If you can complete these problems without help from your text and notes, then you are likely ready to take the exam. Theproblems in the set are NOT the exam questions, however the are very similar in context and difficlty.1) A physical changeA) occurs when propane is burned for heat.B) occurs when iron rusts.C) occurs when glucose is converted into energy within your cells.D) occurs when sugar is heated into caramel.E) occurs when water is evaporated.2) How many significant figures are in the measurement, 0.0005890 g?A) 4 B) 8 C) 6 D) 7 E) 53) What answer should be reported, with the correct number of significant figures, for the following calculation?(433.621 ‐ 333.9) × 11.900A) 1.187 × 103B) 1.1868 × 103C) 1.18680 × 103D) 1.19 × 103E) 1.186799 × 1034) What does it mean to be an exact number? Give an example of an exact number.5) What is the volume (in cm3) of a 63.4 g piece of metal with a density of 12.86 g/cm3?A) .425B) 19.5C) 6.65D) 4.93E) none of the above6) If 1.4% of the mass of a human body is calcium, how many kilograms of calcium are there in a 185‐pound man?A) 5.7 kg Ca B) 1.2 kg Ca C) 5.7 × 102 kg D) 1.2 × 102 kg Ca7) A fishing boat accidentally spills 3.0 barrels of diesel oil into the ocean. Each barrel contains 42 gallons. If the oil film onthe ocean is 2.5 × 102 nm thick, how many square meters will the oil slick cover?A) 1.9 × 106 m2B) 1.9 × 10‐3 m2C) 1.9 × 107 m2D) none of these8) How many protons (p) and neutrons (n) are in an atom of 9038Sr?A) 90 p, 38 nB)38 p, 52 nC)38p, 90 nD)52 p, 38 n9) What does "X" represent in the following symbol?23592XA) copper B) niobium C) tin D) uranium E) palladium10) Which of the following represent isotopes?A: 3215 XB: 3216XC: 3115XD: 3417XA) C and DB)A and DC)A and CD)A and B111) Calculate the atomic mass of silver if silver has 2 naturally occurring isotopes with the following masses and naturalabundances:Ag‐107 106.90509 amu 51.84%Ag‐109 108.90476 amu 48.46%A) 108.00 amu B) 107.79 amu C) 108.32 amu D) 108.19 amu E) 107.90 amu12) How many electrons are in the ion, Cu2+?A) 27 B) 64 C) 31 D) 2913) What mass (in kg) does 5.84 moles of titanium (Ti) have?A) 0.352 kg B) 0.632 kg C) 0.280 kg D) 0.122 kg E) 0.820 kg14) A covalent bond is best described asA) a bond between two polyatomic ions.B) the transfer of electrons.C) a bond between a metal and a polyatomic ion.D) the sharing of electrons between atoms.E) a bond between a metal and a nonmetal.15) Identify the compound with ionic bonds.A) H2O B) Ne C) KBr D) CO E) O216) Identify the compound with covalent bonds.A) KBr B) CH4C) NaCl D) Ne E) Mg17) What is the empirical formula for C4H10O2?A) CHO2B) C2H5OC)CH2O D) CHO E) C2H4O18) Give the name for SnO.A) tin (III) oxide B) tin (II) oxide C) tin (IV) oxide D) tin (I) oxide19) Write the formula for strontium nitride.A) Sr(NO3)2B) Sr3N2C) SrN D) Sr2N3E) Sr(NO2)220) Determine the name for TiCO3. Remember that titanium forms several ions.A) titanium (II) carbonateB) titanium (II) carboniteC) titanium carboniteD) titanium carbideE) titanium (I) carbonate21) Determine the name for CoCl2∙6H2O. Remember that Co forms several ions.A) cobalt (II) chloride heptahydrateB) cobalt (I) chlorideC) cobalt (I) chloride heptahydrateD) cobalt (II) chloride hexahydrateE) cobalt chloride hydrate22) What is the charge on the Cr ions in Cr2O3?A) 1+ B) 2‐ C) 2+ D) 3+223) Write the name for FeS.A) iron (I) sulfide B) iron (I) sulfate C) iron sulfide D) iron (II) sulfate E) iron (II) sulfide24) Write the formula for copper (II) sulfate pentahydrate.A) Cu2SO3∙H5B) CuS∙5H2OC)Cu2S∙H2O D) CuSO4∙5H2O E) (CuSO4)525) Determine the name for H2CO3.A) carbonous acidB) hydrocarbonic acidC) dihydrogen carbonateD) hydrocarbide acidE) carbonic acid26) Determine the name for aqueous HBr.A) hydrobromous acidB) hydrogen bromateC) hydrobromic acidD) bromic acidE) bromous acid27) Give the name for H2SO4.A) persulfuric acidB) sulfuric acidC) sulfurous acidD) hyposulfurous acidE) persulfurous acid28) Determine the name for N2O5.A) nitrogen oxideB) dinitrogen pentoxideC) nitrogen (IV) oxideD) nitrogen (II) oxideE) nitrogen tetroxide29) Calculate the mass percent composition of sulfur in Al2(SO4)3.A) 35.97 % B) 9.372 % C) 42.73 % D) 21.38 % E) 28.12 %30) How many atoms of oxygen are contained in 47.6 g of Al2(CO3)3? The molar mass of Al2(CO3)3 is 233.99 g/mol.A) 3.68 × 1023 O atomsB) 1.23 × 1023 O atomsC) 1.10 × 1024 O atomsD) 2.87 × 1025 O atomsE) 2.96 × 1024 O atoms31) How many SO3 ions are contained in 99.6 mg of Na2SO3? The molar mass of Na2SO3 is 126.05 g/mol.A) 2.10 × 1021 SO3 ionsB) 4.76 × 1020 SO3 ionsC) 1.52 × 1027 SO3 ionsD) 9.52 × 1020 SO3 ionsE) 1.05 × 1021 SO3 ions332) Determine the molecular formula of a compound that has a molar mass of 92.0 g/mol and an empirical formula of NO2.A) NO2B) N2O3C) N3O6D) N2O4E) N2O533) Determine the empirical formula for a compound that is 36.86% N and 63.14% O by mass.A) N2O3B) N2OC)NO D)NO2E) NO334) Write a balanced equation to show the reaction of gaseous ethane with gaseous oxygen to form carbon monoxide gasand water vapor.A) 2 CH3 (g) + 5 O (g) → 2 CO (g) + 3 H2O (g)B) 2 C2H6 (g) + 7 O2 (g) → 4 CO2 (g) + 6 H2O (g)C) C2H6 (g) + 7 O (g) → 2 CO2 (g) + 3 H2O (g)D) C2H6 (g) + 5 O (g) → 2 CO (g) + 3 H2O (g)E) 2 C2H6 (g) + 5 O2 (g) → 4 CO (g) + 6 H2O (g)35) Balance the following equation._____ C10H12 + _____ O2 → _____ H2O + _____ CO236) Methane and oxygen react to form carbon dioxide and water. What mass of water is formed if 0.80 g of methane reactswith 3.2 g of oxygen to produce 2.2 g of carbon dioxide?A) 4.0 g B) 1.8 g C) 3.7 g D) 2.2 g37) Combustion analysis of 1.200 g of an unknown compound containing carbon, hydrogen, and oxygen produced 2.086 g ofCO2 and 1.134 g of H2O. What is the empirical formula of the compound?A) C3H8O2B) C2H5O2C) C2H5OD)C2H10O338) Nitrogen dioxide reacts with water to form nitric acid and nitrigen monoxide. How many moles of NO are formed from8.44 moles of NO2 if there is excess moles of water present?A) 1.83 moles NO B) 2.81 moles NO C) 25.3 moles NO D) 5.63 moles NO E) 8.44 moles NO39) How many moles of nitrogen are formed when 58.6 g of potassium nitrate decomposes to form potassium oxide,molecular nitrogen and molecular oxygen? The molar mass of potassium nitrate