12000 I iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii
X will be in group 5, since if you exchange the valencies of Na with any element on group 5, you will get Na3X
<span>Calculating average atomic mass is exactly like calculating a weighted average. Perform the following calculation:
(mass1)(percentage1) + (mass2)(percentage2) = average atomic mass
(35.0)(0.75) + (37.0)(0.25) = average atomic mass
Make sure your percentages are in decimal form for this calculation.
One of the other answers given is correct, though the explanation is lacking a bit. Two of the answers can be eliminated immediately: 35.0 amu and 37.0 amu cannot be the average. If the mixture of isotopes was 50% and 50%, then 36.0 amu would be correct; however, the mixture is 75/25. This leaves only one possible answer choice.</span>
Answer:
a. withdraws electrons inductively
b. donates electrons by hyperconjugation
c. donates electrons by resonance
d. withdraws electrons inductively
Explanation:
a. The bromide ion is a highly electronegative ion (in the halide series). Electronegative substituents on acids increase the acidity by inductive electron withdrawal method. The higher the electronegativity of a substance, the greater the acidity. The halogens have this order of electronegativity:
F > Cl > Br>I
b. The carboxyl groups have a stabilization of the sigma and pi bonds. This is achieved through a special delocalization of electrons. Because of the delocalization, hyperconjugation is the result effect.
c. The NHCH₃ group has a highly electonegative nitrogen atom that pulls the electron cloud towards itself. In this case, it withdraws electrons inductively. As a result, it donates electrons by resonance.
d. The OCH₃ group has a highly electonegative oxygen atom. This oxygen atom withdraws electron cloud towards itself. As a result, it withdraws electrons inductively.
The following are the answers to the different questions:
<span>The four rows of data below show the boiling points for a solution with no solute, sucrose (C12H22O11), sodium chloride (NaCl), and calcium chloride (CaCl2) (not in that order). Which boiling point corresponds to calcium chloride?
A. 101.53° C
Which of the following solutions will have the lowest freezing point?
D. 1.0 mol/kg magnesium fluoride (MgF2)
Which of the following compounds will be most effective in melting the ice on the roads when the air temperature is below zero?
A. sodium iodide (NaI)
Four different solutions have the following vapor pressures at 100°C. Which solution will have the greatest boiling point?
B. 96.3 kPa
Four different solutions have the following boiling points. Which boiling point corresponds to a solution with the lowest freezing point?
D. 108.1°C</span>
