Question

PLEASE HELP!!



Given the following balanced reaction between hydrochloric acid and oxygen gas to produce water and chlorine gas, how many grams of chlorine gas, Cl2, are produced from 27.8 g of hydrochloric acid and excess oxygen? (To find the molar mass in the problem, use the periodic table and round the mass to the hundreds place for calculation.)

4HCI(aq) +O2 ->2CI2 (g)+ 2H2O (I)

Answer 1

CORRECTION: 4HCI (aq) + O2 (g) -> 2CI2 (g) +2H2O (I)

Answer 2

@hartnn ?

Answer 3

27.8g of HCl x (1 mole of HCl/36.45g of HCl) x (2 moles of Cl2/4 moles of HCl) x (70.9g of Cl2/1 mole of Cl2) = 27.04 grams of Cl2

Answer 4

feel free to ask me any questions about what I just did

Answer 5

My answer choices are: 27.8, 27.0, or 54.0

Answer 6

27.0

Answer 7

Thanks ! Can you help me with some more? Im trying to take my chem final exam and I really need help :(

Answer 8

all I did was convert one type of unit to another using the balanced equation you gave me and the molecular weights of these molecules

Answer 9

lol maybe one more

Answer 10

What is the molar mass of carbonic acid, H2CO3? (Round to four significant figures only.)

Answer 11

To get any molar mass (or technically "weight") of a compound, just add up the individual atomic weights of the atoms that make up the compound

Answer 12

So basically, you need know the atomic weight of H, C, and O by looking at the periodic table and add them up

Answer 13

H weighs about 1 gram/mol and we have two of them so 1x2 = 2 g/mol
C weighs about 12 grams/mol and we have 1 of them so 12x1 = 12 g/mol
O weighs about 16 grams/mol and we have 3 of them so 16x3 = 48 g/mol

So adding them all up gives us 2 + 12 + 48, which is 62 g/mol, which is how much H2CO3 weighs

Answer 14

You can apply what I just showed you to any problem like this now

Answer 15

Thanks :)

Answer 16

Np

Answer 17

Ok so to get ur picture or whatnot on your openstudy profile, are you logging in with your fb account?

Answer 18

Lol that was like......a year and a half ago idr

Answer 19

oh haha

Answer 20

alright good luck on your final exam :)

Answer 21

Just go to settings and click underneath your profile pic

Answer 22

oh sweet thanks!

Answer 23

I gotta put a face behind all of this lol

Answer 24

Elements in group 15 will (gain or lose) electrons to obtain a noble gas structure. How many electrons will the element gain or lose in order to obtain a noble gas structure? (1, 2, 3, 4, 5, 6, 7)

Answer 25

...and viola

Answer 26

how you like? haha

Answer 27

um....

Answer 28

Haha nice pic. are you a doctor?

Answer 29

Almost! I'm a pharmacy (PharmD) student

Answer 30

who's very bored this summer haha

Answer 31

Cool!

Answer 32

So anyways, we really call group 15 as group 5 b/c we ignore the 10 groups that make up the transition metals (middle of the periodic table). Regardless, this refers to the group or row (or family) that starts with Nitrogen

Answer 33

The noble gas group (or row) is 3 rows away

Answer 34

so group 15 (or 5) elements will need to gain 3 electrons to have the noble gas electron configuration

Answer 35

Oh cool I got it right :)

Answer 36

So just count how many columns (sorry NOT "rows" lol) away you are from the noble gas column

Answer 37

**So ya just a correction, groups are COLUMNS not rows sorry haha

Answer 38

rows are called periods

Answer 39

You good now?

Answer 40

In an endothermic reaction, energy _____.

exits the reaction
is absorbed by the reaction
stays the same throughout the reaction

Answer 41

Absorbed

Answer 42

B/c "endo" means IN like absorb

Answer 43

"thermic" basically means energy, which is WHAT is being absorbed

Answer 44

So what do you think "exothermic" means?

Answer 45

non-absorbed? lol

Answer 46

Kinda. What do you think the prefix "ex" (or exo) stands for? In or out?

Answer 47

Out

Answer 48

Exactly

Answer 49

So heat is OUT (or released/exits)

Answer 50

So if this question asked you what "exothermic" was, the answer to that would be the first answer choice, which is "Exits the reaction"

Answer 51

So endothermic and exothermic are opposites

Answer 52

In the formation of table salt, the product, NaCl, has less energy than the reactants, Na and Cl2. This reaction is (exothermic or endothermic)

Would it be exothermic?

Answer 53

in terms of heat/energy flow

Answer 54

Yes nice =D

Answer 55

I see you're chem skills are getting endothermic (hot) haha

Answer 56

Use the standard enthalpies of formation for the reactants and products to solve for the ΔHrxn for the following reaction. (The ΔHf of C2H4 is 52.26 kJ/mol, CO2 is -393.509 kJ/mol, and H2O is -241.818 kJ.)

C2H4 (g) + 3O2(g) 2CO2 (g) + 2H2O(g)

ΔHrxn =

The reaction is






IM SO LOST

Answer 57

Well, I'm going to assume there's a reaction arrow between "3O2(g)" and "2CO2(g)"

Answer 58

to separate the reactants from the products

Answer 59

There is

Answer 60

So the ΔHrxn is the sum of the ΔHformation of products - sum of the ΔHformation of the reactants

Answer 61

and a footnote to make here is that the ΔHformation of "natural" elements like O2(g) (or H2(g), Carbon(graphite), etc) is ZERO

Answer 62

so putting this all together

Answer 63

The ΔHformation for ONE product of H2O(g) is -241.818 kJ and since we have TWO of them, we multiply it by 2. So the total ΔHformation of H2O(g) = 2 x -241.818 = -483.636

Answer 64

We're done with solving for the total ΔHformation of the products so now let's focus on the total ΔHformation of the REACTANTS

Answer 65

Oh wait sorry we still have one more product, which is CO2(g) lol

Answer 66

Ok so the ΔHformation for ONE product of CO2(g) is -393.509 kJ and we have TWO of them so we multiply it by 2. So the total ΔHformation of CO2(g) = 2 x -393.509 = -787.018 kJ

So now we add up the total ΔHformation of H2O and the total ΔHformation of CO2 (which are our two products) to get a grand total of -1270.654kJ. That number is the "sum of ΔHformation of products"

Answer 67

with me so far?

Answer 68

hellooooooooooo

Answer 69

Or do you just want the answer?

Answer 70

So my laptop died. I was 54 questions into the exam out of 98. IM SO PISSED. My teacher is going to make me redo the whole damn thing. And everything is due Monday. UGH.

Answer 71

Oh geez that sux. What are u using now?

Answer 72

I just plugged it in and turned it back on but im locked out of the test now.

Answer 73

Ah darn. You should email your professor about this technical issue. I hope he/she is lenient

Answer 74

It's not entirely your fault

Answer 75

They will probably just send me an alternate test so i'll have to start over :(

Answer 76

:(

Answer 77

That's what I hate about taking tests on computers

Answer 78

Look, if I were you, I would be VERY adamant that I should NOT get an alternate test and that I should be able to finish the remaining questions I have left

Answer 79

Just tell them to "unlock" you from the test

Answer 80

I hope I can do that

Answer 81

Wait do you live in Houston texas?

Answer 82

I feel like I've seen u before

Answer 83

No VA

Answer 84

Ok nevermind lol

Answer 85

Well I hope everything goes you way

Answer 86

I'm sure you'll be fine though

Answer 87

Hey my test got unlocked if you come back online could you help? @aprehan

Answer 88

Awesome. Ya I cud help for a bit