AP Chem 2 Midterm
A lewis diagram for the molecule C2H4 is shown above. In the actual C2H4 molecule H-C-H bond angles are closest to
120 degrees
Which of the following best represents the ground-sate electron configuration for an atom of selenium?
1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^4
Al(s)—> Al^3+(Aquino)+3e- Zn^2(aq)+2e- —>zn(s) The half reactions for the oxidation reduction reaction between Al(s) and Zn^2+(aq) are represented above. Based in the half reactions what is the coefficient for Al(s) if the equation for the oxidation-reduction reaction is balanced with the smallest whole number coefficients?
2
When the equation above is balanced and the coefficients are reduced to the Lowe's whole number terms what is the coefficient of H2O(l)?
2
Ni(s)—> Ni^2+(aq)+2e- Ag+(aq)+e —> Ag(s) Which of the following is the balanced equation for an oxidation-reduction reaction between Ag+(aq) and Ni(s) based on the half reactions represented above?
2Ag+(aq) + Ni(s)—>2Ag(s)+Ni^2+(aq)
Student concluded that a physical change took place but not a chemical. Which of the following could have been the results of the procedure.
A cube of metal was changed into a flat sheet of metal
A 1 mol sample of He(g) at 25 C is mixed with 1 mol sample of Xe(g) at 50 C. Which of the following correctly predicts the changes in averaged kinetic energy and the average speed of the Xe(g) atoms that will occur as the mixture approaches thermal equilibrium?
Average Kinetic Energy of Xe Atoms will decrease Average speed of Xe atoms will decrease
Copper atoms and zinc atoms have the same atomic radius 135 pico-meters, based on this information which of the following diagrams best represents an alloy contains only copper and zinc atoms.
B
The mass spectrum of the elements Sb is most likely represented by which of the following?
B
Occurs when aqueous solutions of ammonia and Venegas are mixed
Brønsted-Lowry acid base reaction
Which of the following molecules is no poplar but has polar covalent bonds?
CCl4
On the basis of the information above, which of the following arranges the binary compounds in order of increasing bond polarity?
CH4<SiCl4<SF4
The diagram above represent solutes present in two different dilute aqueous solutions before they were mixed. Water molecules are not shown. When the solutions were combined, a precipitation reaction took place. Which of the diagrams below is the best particle representation of the mixture after the precipitation occurred?
D
Which of the following statements best accounts for the fact that the peak on the He spectrum is farther to the left and higher than the peak on the H spectrum?
He has a greater nuclear charge than H and an additional electron in the same energy level
Whcih of the following best helps to explain why hexane has a higher boiling point than methanol has?
Hexane molecules have electron clouds that are larger than those of methanol molecules
A student has a 1 g sample of each of the following compounds: NaCl, KBr, and KCl, which of the following lists the samples in order of increasing number of moles in the sample?
KBr<KCl<NaCL
According to the information in the table above, a 1.00 g sample of witch of the following contains the greatest mass of oxygen?
MgO
Which of the following elements has the mass spectrum represented above?
Mo
2F2(g) + 2NaOH(aq)—> OF2(g) + 2NaF(aq) + H2O(l) A 2 mol sample of OF2(g) reacts with excess NaOH(aq) according to the equation above, If the reaction is repeated with excess NaOH(aq) but with 1 mol of F2(g), which of the following is correct?
The amount of OF2 is halved
A student places a sample of a pure metal in a crucible and heats it strongly in air. Data from the experiment are given in the table above. The final mass we determined after the sample was cooled to room temperature. Which of the following statements related to the experiment is correct?
The mass of the sample increased, so a chemical change occurred when bonds formed between the metal and another substance
Which statement describes the changes to the initial pressure of each of each gas and the final partial pressure of each gas in the mixture and also indicates the final total pressure?
The partial pressure of each gas in the moisture is half its initial pressure; the final total pressure is half the sum of the initial pressure of the two gasses.
Two different ionic compounds each contain only copper and chlorine. Both compounds are powders one white and one brown. An element analysis is performed on each powder. Which of the following questions about the compounds is most likely to be answered by the results of the analysis?
What is the formula unit of each compound?