Chemistry XI Unit 1 Questions: 146 Time Limit: 146 minutes Passing Score: 60% Start Quiz Chemistry XI Unit 1 Question 1 of 146 What is the SI unit of mass? kilogram gram milligram metric ton The technique used to determine the composition of a substance is: gravimetry spectroscopy chromatography titration What is the limiting reactant in a reaction? the reactant that has lowest molar mass the reactant that is consumed first the reactant that has highest concentration the reactant that has lowest concentration How many significant figures are there in 0.00456? 2 3 4 5 When 25.0 mL is multiplied by 4.13 g/mL, the result should have: 1 significant figure 2 significant figures 3 significant figures 4 significant figures The formula used to calculate percentage composition is: (mass of element / molar mass) × 100 (mass of element / total mass) × 100 (molar mass / mass of element) × 100 (total mass / mass of element) × 100 Avogadro's number is approximately: 3.22 × 10²³ 6.022 × 10²³ 1.66 × 10⁻²⁴ 6.022 × 10²² The empirical formula is: the actual molecular formula the simplest whole number ratio of atoms the formula with highest number of atoms the formula with lowest molar mass If a compound has empirical formula CH₂ and molar mass 56, its molecular formula is: CH₂ C₂H₄ C₃H₆ C₄H₈ The Law of Conservation of Mass states that: atoms can be created in reactions mass is neither created nor destroyed energy is transformed in reactions mass converts to energy The mass-volume relationship in solutions is best expressed by: Molarity = moles/volume(L) Molarity = mass/volume(mL) Molarity = volume/mass Molarity = moles×volume In stoichiometry, molar ratios are determined from: atomic masses balancing coefficients molecular weights density values What does the term 'standardization' mean in titration? heating a solution to standard temperature determining the exact concentration of a solution diluting a solution to standard volume adjusting pH to neutral The number 5.00 × 10⁻³ has: 1 significant figure 2 significant figures 3 significant figures 4 significant figures Which of the following is an intensive property? mass volume temperature length The density of water is approximately: 0.8 g/cm³ 1.0 g/cm³ 1.2 g/cm³ 1.5 g/cm³ In the reaction: 2H₂ + O₂ → 2H₂O, if 4 moles of H₂ react completely, oxygen needed is: 2 moles 4 moles 1 mole 8 moles What is the molar mass of NaCl? 39.5 g/mol 58.5 g/mol 75.5 g/mol 42.5 g/mol The percent yield formula is: (theoretical yield / actual yield) × 100 (actual yield / theoretical yield) × 100 (theoretical + actual) / 2 × 100 (theoretical - actual) × 100 Which is NOT an assumption of Dalton's Atomic Theory? atoms are indivisible all atoms of same element are identical atoms can be created or destroyed atoms combine in simple ratios The atomic mass unit (amu) is approximately equal to: 1.66 × 10⁻²⁴ g 1.66 × 10⁻²⁷ kg 1/12 mass of C-12 atom all of the above The term 'stoichiometry' refers to: the study of atomic structure calculation of quantities in chemical reactions measurement of temperature changes study of reaction rates When balancing a chemical equation, what is conserved? atoms of each element total charge types of elements number of atoms The formula to find number of moles from mass is: moles = mass × molar mass moles = mass / molar mass moles = molar mass / mass moles = mass + molar mass Which measurement has 4 significant figures? 0.0045 45.00 0.450 0.00450 The volume of 1 mole of ideal gas at STP is: 11.2 L 22.4 L 33.6 L 44.8 L In dilution calculations, the relationship is: M₁V₁ = M₂V₂ M₁ + V₁ = M₂ + V₂ M₁V₁ + M₂V₂ = 0 M₁ / V₁ = M₂ / V₂ The term used for the smallest unit of an ionic compound is: atom ion formula unit molecule What does the symbol Δ in chemistry represent? change triangle approximately delta Which of the following is a heterogeneous mixture? salt water blood air nitrogen The accuracy of measurement is best improved by: reading faster using more precise instruments repeating measurements multiple times heating the sample What is the purpose of rounding in scientific calculations? to make numbers smaller to maintain appropriate significant figures to convert between units to find the average The Law of Definite Proportions states that: different samples of same compound have same element ratio all compounds are made of elements elements have different masses compounds can vary in composition In a 0.5 M solution of NaCl, the number of moles in 2 L is: 0.25 mol 0.5 mol 1.0 mol 2.0 mol The theoretical yield is: the actual amount of product obtained the maximum amount of product possible the amount predicted by limiting reactant calculated from limiting reagent Precision of measurement refers to: how close measurements are to accepted value how close repeated measurements are to each other average of all measurements difference between max and min The molar mass of H₂SO₄ is approximately: 64 g/mol 80 g/mol 98 g/mol 120 g/mol When 0.123 g is divided by 1.23 cm³, the result should have: 1 significant figure 2 significant figures 3 significant figures 4 significant figures The type of reaction where elements combine is called: decomposition synthesis combustion redox In IUPAC nomenclature, what does the suffix 'ane' indicate? alcohol aldehyde single bonds between carbons ether The oxidation number of oxygen in most compounds is: -1 -2 +2 Which process requires absorption of energy? combustion condensation melting fusion The term 'chelation' refers to: bonding of metal to ligand coordination complex formation all of above ligand formation only In qualitative analysis, what is the purpose of identification tests? to determine purity to determine identity of substances to measure quantity to determine color The mass number of an atom equals: number of protons number of neutrons protons + neutrons electrons + neutrons What is the name of the constant 8.314 J/(mol·K)? Boltzmann constant Gas constant Avogadro constant Faraday constant In redox reactions, oxidation is defined as: loss of electrons gain of electrons loss of oxygen gain of hydrogen The pH of a neutral solution at 25°C is: 7 14 between 0-7 Which type of bonding is present in NaCl? covalent ionic hydrogen metallic The number of neutrons in ₁₆⁸O is: 8 16 24 32 Standard state of an element means: most stable form at 25°C and 1 atm any form of element most reactive form least reactive form The process of converting empirical formula to molecular formula requires: only molar mass only empirical formula both empirical formula and molar mass only elemental composition The valency of an element is: same as atomic number number of valence electrons combining capacity of element always positive In stoichiometry problems, conversion factor is: mass/molar mass molar ratio from equation volume/density all of above The term 'substrate' in biochemistry refers to: enzyme product of reaction reactant on which enzyme acts catalyst Half-reactions are most useful in: naming compounds balancing redox equations calculating molar mass determining solubility FILLBLANK:Avogadro's number is approximately _____ particles per mole. 6.022 × 10²³ 3.22 × 10²³ 1.5 × 10²³ 12.044 × 10²³ FILLBLANK:The SI unit of volume is _____ liter centimeter milliliter kilograms FILLBLANK:The process of separating components based on size is called _____ filtration distillation centrifugation chromatography FILLBLANK:In molarity calculations, the formula is M = _____ / Volume(L) moles mass density concentration FILLBLANK:The _____ reactant is consumed completely in a reaction. limiting excess catalyst product FILLBLANK:Percentage composition is calculated as (mass of element / _____) × 100 total mass of compound molar mass of element atomic mass empirical mass FILLBLANK:The molar mass of CO₂ is _____ 44 g/mol 32 g/mol 48 g/mol 56 g/mol FILLBLANK:The _____ formula represents simplest whole number ratio of atoms. empirical molecular structural ionic FILLBLANK:Density is defined as mass per unit _____ volume mass area length FILLBLANK:The law of _____ states mass is neither created nor destroyed. conservation of mass constant proportions definite proportions multiple proportions FILLBLANK:Number of significant figures in 0.00520 is _____ 3 4 2 5 FILLBLANK:In a reaction, the _____ is the ratio of actual to theoretical yield × 100 percent yield theoretical yield actual yield excess yield FILLBLANK:The molar volume of ideal gas at STP is _____ L/mol. 22.4 11.2 44.8 33.6 FILLBLANK:The _____ state is most stable form of element at 25°C and 1 atm. standard excited reactive transition FILLBLANK:The process of separating liquids based on boiling point is _____ distillation filtration crystallization evaporation FILLBLANK:pH = -log [_____] H⁺ OH⁻ H₂O H₃O⁺ FILLBLANK:In the formula M₁V₁ = M₂V₂, this represents the _____ law. dilution conservation proportions stoichiometry FILLBLANK:Oxidation is the _____ of electrons. loss gain transfer sharing FILLBLANK:The _____ is the maximum product possible from stoichiometry. theoretical yield actual yield limiting yield excess yield FILLBLANK:An _____ mixture has uniform composition throughout. homogeneous heterogeneous colloidal suspension FILLBLANK:The _____ is closest measurement to accepted true value. accurate precise repeated estimated FILLBLANK:An element's _____ indicates its combining capacity. valency reactivity polarity electronegativity FILLBLANK:The mass number = protons + _____ neutrons electrons positrons photons FILLBLANK:_____ is the process of identifying substances qualitatively. Qualitative analysis Quantitative analysis Spectral analysis Thermal analysis FILLBLANK:A _____ molar solution contains 1 mole of solute in 1 L of solution. 1 M solution 0.5 M solution 2 M solution 10 M solution FILLBLANK:The _____ of an atom is number of protons. atomic number mass number atomic mass isotope number FILLBLANK:The symbol Δ represents _____ in a quantity. change temperature pressure energy FILLBLANK:Isotopes are atoms with same protons but different _____ neutrons electrons proton number atomic number FILLBLANK:The _____ is the simplest ratio of elements in a compound. empirical formula molecular formula structural formula ionic formula FILLBLANK:Concentration can be expressed as _____ / volume. moles mass density pressure FILLBLANK:The _____ gives quantity relationships in chemical equations. stoichiometry kinetics dynamics equilibrium FILLBLANK:In titration, _____ is the solution of known concentration used. titrant analyte indicator buffer FILLBLANK:An element in its _____ state is at 25°C and 1 atm pressure. standard state excited state ionic state molecular state FILLBLANK:The _____ is measurement how close results are to each other. precision accuracy validity reliability FILLBLANK:The process of calculating product from stoichiometry is called _____ theoretical yield calculation actual yield determination limit calculation excess determination FILLBLANK:Balanced equations show _____ of elements is conserved. number of atoms energy type of reaction reaction rate FILLBLANK:An element's most stable form at 25°C and 1 atm is called its _____ state. standard state reference state normal state average state FILLBLANK:_____ states elements combine in fixed proportions in compounds. Law of Definite Proportions Law of Conservation Law of Constant Composition Law of Multiple Proportions FILLBLANK:Mass number is denoted by _____ and equals protons + neutrons. A Z M N FILLBLANK:The _____ of a solution tells if it's acidic, neutral, or basic. pH value pOH value Kw value Ka value FILLBLANK:A _____ is the smallest unit of an ionic compound. formula unit molecule atom ion TRUE/FALSE: Significant figures in 0.00500 is 3. TRUE FALSE TRUE/FALSE: 1 mole of any ideal gas at STP occupies 44.8 L. TRUE FALSE TRUE/FALSE: Accuracy and precision are the same thing. TRUE FALSE TRUE/FALSE: The limiting reactant is the one in lowest concentration. TRUE FALSE TRUE/FALSE: Dalton's Atomic Theory assumes atoms can be created in reactions. TRUE FALSE TRUE/FALSE: Avogadro's number equals 3.22 × 10²³. TRUE FALSE TRUE/FALSE: The molar mass of O₂ is 32 g/mol. TRUE FALSE TRUE/FALSE: Empirical formula can be same as molecular formula. TRUE FALSE TRUE/FALSE: In dilution, M₁V₁ = M₂V₂ represents conservation of moles. TRUE FALSE TRUE/FALSE: pH of neutral solution at 25°C is always 7. TRUE FALSE TRUE/FALSE: Oxidation always involves loss of oxygen. TRUE FALSE TRUE/FALSE: Electron configuration follows Aufbau principle. TRUE FALSE TRUE/FALSE: Ionic bonds exist between atoms in NaCl. TRUE FALSE TRUE/FALSE: Percentage composition can exceed 100%. TRUE FALSE TRUE/FALSE: Molar mass is always numerically equal to atomic/molecular mass. TRUE FALSE TRUE/FALSE: Limiting reactant remains after reaction completes. TRUE FALSE TRUE/FALSE: Standard state is defined at 25°C and 1 atm pressure. TRUE FALSE TRUE/FALSE: Double displacement reactions always produce a precipitate. TRUE FALSE TRUE/FALSE: Extensive properties depend on amount of substance. TRUE FALSE TRUE/FALSE: Molarity is always greater than molality. TRUE FALSE TRUE/FALSE: Isotopes of same element have different atomic numbers. TRUE FALSE TRUE/FALSE: Atomic mass unit is 1/12 of mass of C-12 atom. TRUE FALSE TRUE/FALSE: Half-life is constant for radioactive elements. TRUE FALSE TRUE/FALSE: Heat is form of energy expressed in joules. TRUE FALSE TRUE/FALSE: Heterogeneous mixture has uniform composition. TRUE FALSE TRUE/FALSE: Balancing chemical equation changes subscripts in formulas. TRUE FALSE TRUE/FALSE: All elements can form more than one oxidation state. TRUE FALSE TRUE/FALSE: Reduction half-reaction shows gain of electrons. TRUE FALSE TRUE/FALSE: Percent yield is always 100%. TRUE FALSE TRUE/FALSE: Molarity of solution remains constant upon heating. TRUE FALSE TRUE/FALSE: Elements in Periodic Table arranged by increasing atomic number. TRUE FALSE TRUE/FALSE: Covalent bonds involve sharing of electron pairs. TRUE FALSE TRUE/FALSE: Electronegativity increases from left to right in period. TRUE FALSE TRUE/FALSE: Noble gases are very reactive elements. TRUE FALSE TRUE/FALSE: pH below 7 indicates basic solution. TRUE FALSE TRUE/FALSE: Titration is used to determine concentration of solution. TRUE FALSE TRUE/FALSE: Synthesis reaction combines two or more substances. TRUE FALSE TRUE/FALSE: Exothermic reactions release heat energy. TRUE FALSE TRUE/FALSE: Precision requires accurate instrument. TRUE FALSE TRUE/FALSE: Coordination number indicates total number of atoms. TRUE FALSE TRUE/FALSE: Hydration enthalpy is always negative. TRUE FALSE TRUE/FALSE: Compound always contains two or more elements. TRUE FALSE TRUE/FALSE: Homogeneous mixture can be separated by filtration. TRUE FALSE TRUE/FALSE: Mass number can be different for isotopes of same element. TRUE FALSE TRUE/FALSE: Oxidation state of element in elemental form is zero. TRUE FALSE TRUE/FALSE: Valency of Cl in NaCl is -1. TRUE FALSE TRUE/FALSE: Formation of ionic bond releases energy. TRUE FALSE TRUE/FALSE: Electron affinity increases up a group. TRUE FALSE TRUE/FALSE: Solution with pH 3 is more acidic than pH 5. TRUE FALSE Previous Next Submit Quiz Want to save your progress? Create an account or log in to track your quiz scores! Register/Login