[ftskftsk]

im having trouble, any help would be appreciated as I would need this to study for the final, which is tomorrow unfortunately.


here are the questions:(some I have answered but need confirmation if they are correct)



1. What mass in grams of potassium is produced if 100.g of potassium chlorate decompose according to the following equation?
2KCLO3(s) → 2KCL(s) + 3O2(g)



2. Why should you use moles in stoichiometric problems?


3. At a winter carnival, a balloon is filled with 5.00 L of helium at a temperature of 273 K.  What will be the volume of the balloon when it is brought into

a warm house at 295 K?(i got 5.4) please correct me if wrong.



4. The air in a person's lungs consists of 0.177 mol of gas particles at 310 K and 101.3 kPa pressure.  What is the volume of the air?(i got 4.5) please

correct me if im wrong.



5. Formamide, HCONH2, is used to manufacture agricultural chemicals, dyes, and pharmaceuticals.  At 125°C, formamide decomposes.
HCONH2(g) ← → NH3(g) + CO(g)
If Keq is 4.8 and the concentrations of NH3(g) and CO(g) are both 0.20 mol/L at equillibrium, what is the concentration of formamide?



6. If 20.0ml of 0.20 M aqueous HNO₃ are required to titrate 25 mL of an aqueous solution of NaOH, what is the molarity of the NaOH solution? Use

the formula: C_acidV_acid=C_baseV_base



7. List the major differences between the arrhenius and the Bronsted-lowry definitions of acids and bases.(i got:   arrthenius/Bronsted lowry bases - gives

off OH^-in water.
Arrthenius/Bronsted lowry acids - give H⁺ in water.)please correct if im wrong.



8. Why Must reduction always be accompanied by oxidation?




9. A certain electrochemical cell has Zn + HgO → AnO +Hg for its cell reaction.  Write the reaction that is occuring at each electrode.


e. Cahode:
____________________________________________________

f.  Anode:
____________________________________________________








10. Use the concepts of elecrostatic repulsion and strong nuclear force to explain why some atoms decay.





11. Predict the product of the nuclear reaction shown in the reaction:
²⁴⁶₉₆Cm + ¹²₆ → 4 ¹₀n + _________________.
b. Which radioactive particle does the Carbon-12 isotope resemble? _______________________





12. Explain in terms of nuclear force and electrostatic charge why nuclear stability increases for nuclei with atomic numbers lower than iron-56 and

nickel-58 but decrease for atomic nuclei greater than iron-56 and nickel-58.

THANK YOU!

[ftskftsk]

where can i edit? anyways i  made a mistake with the subscripts and superscripts codes in my initial post, here is  a fix:



1. What mass in grams of potassium is produced if 100.g of potassium chlorate decompose according to the following equation?
2KCLO3(s) → 2KCL(s) + 3O2(g)



2. Why should you use moles in stoichiometric problems?


3. At a winter carnival, a balloon is filled with 5.00 L of helium at a temperature of 273 K.  What will be the volume of the balloon when it is brought into

a warm house at 295 K?(i got 5.4) please correct me if wrong.



4. The air in a person's lungs consists of 0.177 mol of gas particles at 310 K and 101.3 kPa pressure.  What is the volume of the air?(i got 4.5) please

correct me if im wrong.



5. Formamide, HCONH2, is used to manufacture agricultural chemicals, dyes, and pharmaceuticals.  At 125°C, formamide decomposes.
HCONH2(g) ← → NH3(g) + CO(g)
If Keq is 4.8 and the concentrations of NH3(g) and CO(g) are both 0.20 mol/L at equillibrium, what is the concentration of formamide?



6. If 20.0ml of 0.20 M aqueous HNO₃ are required to titrate 25 mL of an aqueous solution of NaOH, what is the molarity of the NaOH solution? Use

the formula: C_acidV_acid=C_baseV_base



7. List the major differences between the arrhenius and the Bronsted-lowry definitions of acids and bases.(i got:   arrthenius/Bronsted lowry bases - gives

off OH^-in water.
Arrthenius/Bronsted lowry acids - give H⁺ in water.)please correct if im wrong.



8. Why Must reduction always be accompanied by oxidation?




9. A certain electrochemical cell has Zn + HgO → AnO +Hg for its cell reaction.  Write the reaction that is occuring at each electrode.


e. Cahode:
____________________________________________________

f.  Anode:
____________________________________________________








10. Use the concepts of elecrostatic repulsion and strong nuclear force to explain why some atoms decay.





11. Predict the product of the nuclear reaction shown in the reaction:
²⁴⁶₉₆Cm + ¹²₆ → 4 ¹₀n + _________________.
b. Which radioactive particle does the Carbon-12 isotope resemble? _______________________





12. Explain in terms of nuclear force and electrostatic charge why nuclear stability increases for nuclei with atomic numbers lower than iron-56 and

nickel-58 but decrease for atomic nuclei greater than iron-56 and nickel-58.

[Borek]

Please read forum rules.

You have to show your attempts to receive help. This is a forum policy.

[ftskftsk]

I have reviewed my post, questions 3,4,5 were all completed by me, im asking that someone review them to let me know i did them correctly, im also asking that i receive help with the other questions, as i have only tonight to study. as for posting the questions twice, it will not happen again  if anyone can please help it would be appreciated, even if its just a question.

[ftskftsk]

ok ive been checking around online and i was able to solve a few of them.


for 2. becase in atomical terms, moles are the most accurate.


3. 5.4


4. 4.5


7. 0.16


8. Bases- gives off OH- in water
acids- gives of H+ in water

9. the reaction wouldn't be a redox otherwise. the number of electrons must equal the number of electrons gained.



are those correct? and can anyone help with the remaining problems?

thanks!

[ftskftsk]

thanks for the help guys.. -.-
i just took my chem exam yesterday, and without your help, i managed to do a decent job on the test.
anyways happy cheming?goodbye.

[sjb]

I'm happy you managed to cope OK. Part of the problem was that the board was offline for quite a while yesterday, so we may not have been able to get to help, and also it's not overly clear where your working is for those mathematical problems that you have answered.

For 1, where does your product list show potassium?

For 2, I'd've thought it would be more accurate to take a mass, rather than counting billions of atoms, so I'm not sure that's the best answer.

3, 5.4 what? pints (UK / US?), cups?..

4, again, check your units

5, What's your expression for Kc?

6, simple plugging into the equation and rearranging to find Cbase

7, I think the question is asking for the difference between Lowry-Broensted and Arrhenius, rather than between acid and base

8, sounds fine

9, what process occurs at the cathode - oxidation or reduction? Can you write an equation ignoring spectator ions.

10 seems a bit advanced for high school, but what do you know of the strong nuclear force?

11, balance your protons and nucleons

12, again, perhaps a bit advanced for high school, how much do you know on this topic?