The given question is incomplete. The complete question is:
The change in entropy is related to the change in the number of moles of gas molecules. Determine the change in moles of gas for each of the reactions and decide if the entropy increases decreases or has little to no change:
A. 
B. 
C. 
D. 
Answer: A. : decreases
B. 
: decreases
C. : no change
D. : increases
Explanation:
Entropy is defined as the randomness of the system.
Entropy is said to increase when the randomness of the system increase, is said to decrease when the randomness of the system decrease and is said to have no change when the randomness remains same.
In reaction , as gaseous reactant is changed to solid product, entropy decreases.
In reaction , as 4 moles of gaseous reactants is changed to 2 moles of gaseous product, entropy decreases.
In reaction , as 3 moles of gaseous reactants is changed to 3 moles of gaseous product, entropy has no change.
In reaction , as 1 mole of gaseous reactant is changed to 3 moles of gaseous product, entropy increases.
Answer:65.4 meters= 65400 millimeters
Answer:
Explanation:
From the net ionic equation
Ba2+(aq) + SO42-(aq) ==> BaSO4(s) we see that 1 mole Ba2+ reacts with 1 mole SO42- to -> 1 mol BaSO4
Find moles of Ba2+ used: 0.250 moles/L x 0.0323 L = 0.008075 moles Ba2+
Find moles SO42- present: 0.008075 moles Ba2+ x 1 mol SO42-/1 mol Ba2+ = 0.008075 mol SO42-
Find mass of Na2SO4 present: 0.008075 mol SO42- x 1 mol Na2SO4/1 mol SO42- x 142.04 Na2SO4/mole = 1.14698 g = 1.15 g Na2SO4 (to 3 significant figures)
Answer: Electronegativity increases as the size of an atom decrease.
Explanation: Electronegativity is the measure of the ability of an atom in a bond to attract electrons to itself.
Electronegativity increases across a period and decreases down a group.
Towards the left of the table, valence shells are less than half full, so these atoms (metals) tend
to lose electrons and have low electronegativity. Towards the right of the table, valence shells are more than half full, so these atoms (nonmetals) tend to gain electrons and have high electronegativity.
Down a group, the number of energy levels (n) increases, and so does the distance between the nucleus and the outermost orbital. The increased distance and the increased shielding weaken the nuclear attraction, and so an atom can’t attract electrons as strongly.
