Question

A liquid is placed in an evacuated, sealed flask. When will this closed system reach dynamic equilibrium?

When all of the liquid has evaporated to form a vapor
When liquid and vapor are present but evaporation stops
When the rate of evaporation equals the rate of condensation
When the volume of liquid equals the volume of vapor

Answer 1

@taramgrant0543664 b?

Answer 2

B makes sense because the rate of condensation is much slower than the rate of evapouration

Answer 3

@taramgrant0543664 that was wrong

Answer 4

Wait I didn't really like that answer so I wanted to double check and it should have been c. I assumed that evapouration would get ahead but it stays constant the condensation speeds up to accomidate making the rates equal

Answer 5

Two gases are placed in a sealed flask and allowed to react. Which statement is true about the concentrations of the reactants and products when this closed system reaches dynamic equilibrium?

They will be equal and constant.

They will be equal but continuously changing.

They will not necessarily be equal, and they will be continuously changing.

They will not necessarily be equal, but they will be constant.

Answer 6

this one was wrong too we had picked c

Answer 7

It could've been d

Answer 8

it was thanks

Answer 9

What is the oxidation number of fluorine (F) in F2?

+1
−1
0
−3

Answer 10

d?

Answer 11

@taramgrant0543664

Answer 12

They should be electrically neutral

Answer 13

When F2 bond to another, the oxidation # on each atom is 0. If oxidation state is maintained at -1, it would lead the molecule to have a net -2 charge. Such oxidation # assignment is inaccurate, since F2 molecules are electrically neutral.

Answer 14

so 0 would be correct

Answer 15

Yes

Answer 16

Which of the following describes an element that is oxidized in a reaction?

It gains electrons during a reaction.
It has a decrease in its oxidation number.
Al yields Al3+ + 3e−
F2 + 2e− yields 2 F−

Answer 17

a?

Answer 18

@sweetburger

Answer 19

In oxidation you. Lose electrons

Answer 20

so b? @taramgrant0543664

Answer 21

C is an oxidation reaction, it's not B because if you lose electrons you become more positive increasing the oxidation number, it's not D as that is a reduction reaction and a is describing the reduction reaction

Answer 22

Which of the following chemical reactions is an oxidation-reduction reaction?

CuSO4 + BaCl2 yields BaSO4 + CuCl2
AgNO3 + NaCl yields AgCl + NaNO3
Pb(NO3)2 + 2NaCl yields PbCl2 + 2NaNO3
Zn + H2SO4 yields ZnSO4 + H2

Answer 23

b? @taramgrant0543664

Answer 24

Check the charges on each element for the product side and reactant side. If any element had a change in its charge, it's an oxidation/reduction reaction.

AgNO3 + NaCl --> AgCl + NaNO3

Reactant side:
Ag has a charge of +1
N has a charge of + 5
O has a charge of - 2 (-2 * 3 = -6 total)
Na has a charge of +1
Cl has a charge of -1

Product side:
Ag has a charge of +1
Cl has a charge of -1
Na has a charge of +1
N has a charge of +5
O has a charge of -2

No species in the reaction had a change in charge meaning it's not a reduction/oxidation reaction.

Answer 25

so d is corrrect?

Answer 26

Yes D is correct

Answer 27

Consider the following reaction:

Cl2 + 2NaBr yields 2NaCl + Br2

Which element is oxidized and which is reduced in the reaction?

Br is reduced and Na is oxidized.
Cl is reduced and Br is oxidized.
Cl is reduced and Na is oxidized.
Na is reduced and Br is oxidized.

Answer 28

a? @taramgrant0543664

Answer 29

Left side
Cl -> 0
Na -> +1
Br -> -1

Right side
Cl -> -1
Na-> +1
Br-> 0

Lose electrons oxidized, gain electrons reduced

Answer 30

so c

Answer 31

Cl is being reduced, but Ana the charge remains the same so it is not being oxidized or reduced

Answer 32

B IS CORRECT?

Answer 33

Yes it is B, Br is losing electrons and therefore oxidized

Answer 34

What is true of an element that was reduced in a chemical reaction?

It lost electrons.
It gained electrons.
It increased electronegativity.
It decreased electronegativity.

Answer 35

A? @taramgrant0543664

Answer 36

If it loses electrons it's oxidized, if it gains electrons it's reduced

Answer 37

d?

Answer 38

If it was reduced then it should have gained electrons, it does not affect electronegativity

Answer 39

b is correct?

Answer 40

Yes

Answer 41

Which of the following describes an element that is reduced in a reaction?

It acts in the reactant that is the reducing agent.
It has a decrease in its oxidation number.
Cd yields Cd2+ + 2e−
Zn + Cu2+ yields Zn2+ + Cu

Answer 42

Well we can take out A since the reducing agent donates or loses electrons so if it loses electrons it becomes oxidized. We can also rule out B because the number wouldn't decrease it would increase

Answer 43

D is a redox reaction so c is the only one specifically referring to an element that is being reduced

Answer 44

@taramgrant0543664 c is wrong

Answer 45

so d should be correct?

Answer 46

I'm pretty sure a and b are wrong so then I guess it must be D

Answer 47

ok