Chemistry Questions

Which change is exothermic?(1) freezing of water(2) melting of iron(3) vaporization of ethanol(4) sublimation of iodine
1 Answers
An Arrhenius acid has(1) only hydroxide ions in solution(2) only hydrogen ions in solution(3) hydrogen ions as the only positive ions in solution(4) hydrogen ions as the only negative ions in solution
2 Answers
The reaction between an organic acid and an alcohol produces(1) an aldehyde (3) an ether(2) a ketone (4) an ester
2 Answers
Which statement must be true for any chemical reaction at equilibrium?(1) The concentration of the products is greater than the concentration of the reactants.(2) The concentration of the products is less than the concentration of the reactants.(3) The concentration of the products and the concentration of the reactants are equal.(4) The concentration of the products and the concentration of the reactants are constant.
2 Answers
At standard pressure, CH4 boils at 112 K and H2O boils at 373 K. What accounts for the higher boiling point of H2O at standard pressure?(1) covalent bonding (3) hydrogen bonding(2) ionic bonding (4) metallic bonding
2 Answers
In which process does a solid change directly into a vapor?(1) condensation (3) deposition(2) sublimation (4) solidification
1 Answers
In which compound does chlorine have the highest oxidation number?(1) NaClO (3) NaClO3(2) NaClO2 (4) NaClO4
1 Answers
Which solution reacts with LiOH(aq) to produce a salt and water?(1) KCl(aq) (2) CaO(aq) (3)NaOH(aq) (4)H2SO4(aq)
1 Answers
Given the balanced equation:4Fe(s) + 3O2(g) ==>2Fe2O3(s) + 1640 kJWhich phrase best describes this reaction?(1) endothermic with DH = +1640 kJ(2) endothermic with DH = -1640 kJ(3) exothermic with DH = +1640 kJ(4) exothermic with DH = -1640 kJ
1 Answers
The average kinetic energy of water molecules is greatest in which of these samples?(1) 10 g of water at 35°C(2) 10 g of water at 55°C(3) 100 g of water at 25°C(4) 100 g of water at 45°C
2 Answers
The vapor pressure of a liquid is 0.92 atm at 60°C. The normal boiling point of the liquid could be(1) 35°C (3) 55°C(2) 45°C (4) 65°C
2 Answers
Which statement compares the masses of two subatomic particles?(1) The mass of an electron is greater than the mass of a proton.(2) The mass of an electron is greater than the mass of a neutron.(3) The mass of a proton is greater than the mass of an electron.(4) The mass of a proton is greater than the mass of a neutron.
2 Answers
A solution contains 35 grams of KNO3 dissolved in 100 grams of water at 40°C. How much more KNO3 would have to be added to make it a saturated solution?(1) 29 g (3) 12 g(2) 24 g (4) 4 g
2 Answers
Given the redox reaction:Cr3+ + Al-->Cr + Al3+As the reaction takes place, there is a transfer of(1) electrons from Al to Cr3+(2) electrons from Cr3+ to Al(3) protons from Al to Cr3+(4) protons from Cr3+ to Al
2 Answers
15 Which statement describes the particles of an ideal gas, based on the kinetic molecular theory?(1) The motion of the gas particles is orderly and circular.(2) The gas particles have no attractive forces between them.(3) The gas particles are larger than the dis­tances separating them.(4) As the gas particles collide, the total energy of the system decreases.
2 Answers
Which statement about a system at equilibrium is true?(1) The forward reaction rate is less than the reverse reaction rate.(2) The forward reaction rate is greater than the reverse reaction rate.(3) The forward reaction rate is equal to the reverse reaction rate.(4) The forward reaction rate stops and the reverse reaction rate continues.
2 Answers
What is the percent by mass of oxygen in propanal, CH3CH2CHO?(1) 10.0% (3) 38.1%(2) 27.6% (4) 62.1%
2 Answers
According to Table I, which equation represents a change resulting in the greatest quantity of energy released? 2C(s) + 3H2(g) → C2H6(g) 2C(s) + 2H2(g) → C2H4(g) N2(g) + 3H2(g) → 2NH4(g) N2(g) + O2(g) → 2NO(g)
1 Answers