6.4-6.6
Consider the following balanced chemical equation: 2NO(g) + Cl2(g) → 2NOCl(g) If 12 molecules of NO are allowed to react with 10 molecules of Cl2, how many molecules of NOCl will be formed? A. 12 molecules of NOCl B. 20 molecules of NOCl C. 2 molecules of NOCl D. 1 molecule of NOCl
A
Select all the statements that correctly describe the limiting reactant in a reaction. A. When two reactants are mixed together and are not present in the exact mole ratio, we will have too much of one reactant and not enough of another. B. The maximum amount of product formed is the amount that can be formed from the limiting reactant. C. The limiting reactant is always the reactant present in the lowest mass amount. D. There will always be limiting reactant left over after the reaction is complete. E. The limiting reactant limits the amount of product(s) that can form.
A, B, & E
Consider the following balanced chemical equation: CO(g) + 2H2(g) → CH3OH(g) If 7 molecules of CO are reacted with 12 molecules of H2, how many molecules of CH3OH can be formed? A. 7 molecules of CH3OH B. 6 molecules of CH3OH C. 14 molecules of CH3OH D. 12 molecules of CH3OH
B
Consider the following balanced chemical equation: SiH4(g) + 2O2(g) → SiO2(s) + 2H2O(g) If 7 molecules of SiH4 are allowed to react with 13 molecules of O2 what is the limiting reactant? A. SiH4 B. O2 C. SiO2 D. H2O
B
Select all of the statements that correctly describe heat. A. Heat may be transferred from the colder to the hotter object in certain situations. B. Heat is the amount of energy that is transferred between two objects because of a difference in their temperatures. C. Two objects that are at different temperatures and are in contact with one another will reach thermal equilibrium.
B & C
Select all of the statements that correctly describe the calorie. A. The amount of heat needed to raise the temperature of 1 mole of water by 1°C. B. 1 calorie = 4.184 joules C. The amount of heat needed to raise the temperature of 1 g of water by 1°C. D. 4.184 calories = 1 joule
B & C
Consider the following balanced chemical equation: 2Al(s) + 3Cl2(g) → 2AlCl3(s) Suppose that eight atoms of Al(s) are reacted with nine molecules of Cl2(g). Select the statements that correctly describe this chemical reaction. A. Two formula units of AlCl3 will be formed. B. Cl2(g) is the limiting reactant. C. Al(s) is the limiting reactant. D. Six formula units of AlCl3 will be formed.
B & D
Select the statements that are consistent with the law of conservation of energy. A. Energy can be transferred as heat and subsequently used up by the surroundings. B. Energy can be converted from one form into another. C. Energy may be created and destroyed in certain chemical reactions. D. Energy cannot be created or destroyed.
B & D
1 mole of CO2 is formed from its elements and the value of q for this system is -394 kJ. What change (if any) is occurring? A. The system gains heat. B. The system neither gains nor loses heat. C. The system loses heat.
C
24 kJ of energy is required to heat a 250-g sample of aluminum from 10oC to 117oC. What is the specific heat of aluminum? A. 0.82 J/(g oC) B. 9.6 J/(g oC) C. 0.90 J/(g oC)
C
A 102.0-g sample of water is cooled from 25.6oC to 16.7oC. Given that the specific heat of water is 4.184 J/(g oC), calculate the value of q for this process. A. -7.1 kJ B. +3.8 kJ C. -3.8 kJ D. +7.1 kJ
C
An _____ reaction is a reaction in which the _____ contain less potential energy than the _____. A. endothermic, products, reactants B. exothermic, reactants, products C. exothermic, products, reactants
C
A 5.2-g piece of metal is heated and placed in a calorimeter that is filled with 120 g of water that is at 23.5oC. The water reaches a final temperature of 74.3oC. Calculate the heat change for the piece of metal (the specific heat of water is 4.184 J/(g oC)). A. -37.3 kJ B. +37.3 kJ C. +25.5 kJ D. -25.5 kJ
D
Consider the following balanced chemical equation: 2B4H10(s) + 11O2(g) → 4B2O3(s) + 10H2O(g) If 23 molecules of O2 are allowed to react with 2 molecules of B4H10, what is the limiting reactant? A. O2 B. B2O3 C. H2O D. B4H10
D
Consider the following balanced chemical equation: 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(l) If 0.76 moles of NH3 are reacted with 0.80 moles of O2, what is the limiting reactant? A. NH3 B. NO C. H2O D. O2
D
Consider the following balanced chemical equation: CaC2(s) + 2H2O(l) → Ca(OH)2(s) + C2H2(g) If 2.0 g of CaC2 are completely reacted with water to give 2.0 g of Ca(OH)2, what is the percent yield of Ca(OH)2? The molar masses of CaC2 and Ca(OH)2 are 64.1 g/mol and 74.1 g/mol, respectively. A. 100% B. 64% C. 50% D. 87%
D
Consider the following balanced chemical equation: Pb(NO3)2(aq) + 2KI(aq) → PbI2(s) + 2KNO3(aq) If 1.70 g of Pb(NO3)2 are reacted with 3.40 g of KI, how many grams of PbI2 will be produced? The molar masses of Pb(NO3)2, KI, and PbI2 are 331.22, 166.00, and 461.00 g/mol, respectively. A. 1.70 g B. 3.40 g C. 9.45 g D. 2.36 g
D
______ is the amount of energy that is transferred between two objects because of a difference in their temperatures. A. Thermal equilibrium B. Specific heat C. A kilojoule D. Heat
D
Select all of the statements that are consistent with the term percent yield. Multiple select question. A. Percent yield = actual yield/theoretical yield x 100% B. Percent yield describes how much of a product is actually formed in comparison to how much should have been formed. C. Percent yield = theoretical yield/actual yield x 100% D. Percent yield is the amount of product that is measured to have formed from a chemical reaction.
A & B
Select all of the statements that correctly describe a system and its surroundings. A. The surroundings are everything that surround a system. B. Heat absorbed by a system comes from its surroundings. C. Heat released by a system is not transferred to its surroundings.
A & B
An endothermic reaction is ______. A. a reaction that releases energy to the surroundings and is described as an "uphill" reaction. B. a reaction that may absorb or release heat. C. a reaction that absorbs energy from the surroundings and is described as an "uphill" reaction. D. a reaction that absorbs energy from the surroundings and is described as a "downhill" reaction.
C
Consider the following balanced chemical equation: 3Cu(s) + 8HNO3(aq) → 3Cu(NO3)2(aq) + 4H2O(l) + 2NO(g) If 4.42 moles of Cu(s) is reacted with 9.06 moles of HNO3(aq), what is the limiting reagent? A. Cu B. NO C. HNO3 D. Cu(NO3)2 E. H2O
C
Consider the following balanced chemical equation: 3Ge(s) + 4HNO3(l) → 3GeO2(s) + 4NO(g) + 2H2O(l) If 5.01 moles of Ge are completely reacted with HNO3 to give 4.36 moles of NO, what is the percent yield of NO? A. 80.0% B. 75.0% C. 65.3% D. 87.0%
C
If the value of q for a system is +3.5 kJ what change is occurring (if any)? A. The system is losing heat. B. The system is neither gaining nor losing heat. C. The system is gaining heat.
C
The _____ yield is defined as the _____ amount of product that can be obtained from a chemical reaction. A. actual, minimum B. actual, maximum C. theoretical, maximum D. percent, maximum E. theoretical, minimum
C
The ____ ratio and the mole ratio are related to the coefficients in the balanced chemical equation.
molecule
Consider the following balanced chemical equation: Al2S3(s) + 6H2O(l) → 2Al(OH)3(s) + 3H2S(g) If 0.98 mol of Al2S3 is reacted with 5.98 mol of H2O, how many moles of H2S will be produced? A. 2.94 mol B. 8.94 mol C. 0.98 mol D. 2.98 mol
A
Consider the following balanced chemical equation: Zn(s) + 2O2(g) + S(s) → ZnSO4(s) If 5.78 g of Zn are allowed to react with 3.00 g of O2 and excess sulfur, how many grams of ZnSO4 will be produced? The molar masses of Zn, O2, and ZnSO4 are 65.41, 32.00, and 161.48 g/mol, respectively. A. 7.57 g B. 3.00 g C. 14.3 g D. 5.78 g
A
Given a certain amount of reactants, the maximum amount of product that can be obtained from a chemical reaction is known as the _____ yield. A. theoretical B. percent C. actual
A
How many calories are there in 6.879 joules? A. 1.644 calories B. 28.78 calories C. 287,800 calories D. 6.879 calories E. 1644 calories
A
Which of the following equations correctly relates specific heat (C), heat (q), temperature change (ΔT), and mass (m)? A. q = m x C x ΔT B. m = q x C x ΔT C. ΔT = q x C x m D. C = q x m x ΔT
A
he ______ reactant in a reaction is one that limits the amount of product formed. This reactant will be completely used up in the reaction. Any reactants that are not used up are said to be ______. A. limiting, present in excess B. lightest, lost C. lightest, present in excess D. heaviest, present in excess E. limiting, lost
A
Select all of the statements that correctly describe an endothermic reaction. A. An endothermic reaction is a reaction where energy is absorbed from the surroundings. B. An endothermic reaction is described as being "uphill" since the products contain more potential energy than the reactants. C. An endothermic reaction is described as being "uphill" since the reactants contain more potential energy than the products. D. An endothermic reaction is a reaction where energy is released to the surroundings.
A & B
Select all of the statements that correctly describe an exothermic reaction. A. The products are lower in energy than the reactants B. Energy is released during an exothermic reaction. C. An exothermic reaction is described as being "uphill" since the reactants contain more potential energy than the products.
A & B
Select all of the statements that correctly describe the molecule ratio. A. The molecule ratio is the same as the mole ratio. B. The molecule ratio and the mole ratio are related to the coefficients in the balanced chemical equation. C. The molecule ratio for any reaction is the same as the mass ratio.
A & B
Select the statements that correctly define specific heat. A. The amount of heat that must be added to 1 g of a substance to raise its temperature by 1°C is the specific heat of the substance. B. The amount of heat that must be added to 1 mole of a substance to raise its temperature by 1°C is the specific heat of the substance. C. Specific heat is measured in J/(g oC) or cal/(g oC)
A & C
Consider the following balanced chemical equation: Cu(s) + 2H2SO4(l) → CuSO4(aq) + 2H2O(l) + SO2(g) Suppose 8 molecules of H2SO4 are reacted with 7 atoms of Cu. Select the statements that correctly describe this reaction. A. H2SO4(l) is the limiting reactant. B. Eight molecules of SO2 will be formed. C. Cu(s) is the limiting reactant. D. Four molecules of SO2 will be formed.
A & D
The amount of product that is measured to have been formed from a chemical reaction is the ______. A. percent yield B. actual yield C. theoretical yield
B
