Fun Chem Questions

[dvduplex]

---

Members don't see this ad.

hey everyone,

I need help on a couple of chem questions. here are the questions:

1. Concentrated sulfuric acid is 18M. What volume of water would be needed to dilute 25mL of concentrated H2SO4 solution to 3M?

2. How many moles of AgIO3 (Ksp= 3x10^-8) will dissolve in one liter of a 10^-5M solution of NaIO3?

3. Why does raising the temperature cause an increase in the rate of a chemical reaction?

4. In the kaplan bb, it said that increase branching causes an decrease in Boiling point and Melting point. But in destroyer, when there is a increase in branching, there would be a increase in melting point and a decrease in boiling point. So, which one is true and why?

thank you!🙂

 

[whoaaitzkyle]

hey everyone,

I need help on a couple of chem questions. here are the questions:

1. Concentrated sulfuric acid is 18M. What volume of water would be needed to dilute 25mL of concentrated H2SO4 solution to 3M?

2. How many moles of AgIO3 (Ksp= 3x10^-8) will dissolve in one liter of a 10^-5M solution of NaIO3?

3. Why does raising the temperature cause an increase in the rate of a chemical reaction?

4. In the kaplan bb, it said that increase branching causes an decrease in Boiling point and Melting point. But in destroyer, when there is a increase in branching, there would be a increase in melting point and a decrease in boiling point. So, which one is true and why?

thank you!🙂

1. Since this is dilution, you use M1V1=M2V2.
(18M)(25mL)=(3M)(V2)

 

[whoaaitzkyle]

hey everyone,

I need help on a couple of chem questions. here are the questions:

1. Concentrated sulfuric acid is 18M. What volume of water would be needed to dilute 25mL of concentrated H2SO4 solution to 3M?

2. How many moles of AgIO3 (Ksp= 3x10^-8) will dissolve in one liter of a 10^-5M solution of NaIO3?

3. Why does raising the temperature cause an increase in the rate of a chemical reaction?

4. In the kaplan bb, it said that increase branching causes an decrease in Boiling point and Melting point. But in destroyer, when there is a increase in branching, there would be a increase in melting point and a decrease in boiling point. So, which one is true and why?

thank you!🙂

I THINK for #2 you write the equation out first:

AgIO3 ---> Ag2+ + 2IO3-

3x10^-8 = (x)(2x)^2, by adding NaIO3- you're contributing more IO3- ions so add it with the (2x)^2 area -----> (2x+ 1x10^-5)

Assume x is really small.

3x10^-8 = (x)(1x10^-5) and solve... I think that's how you're supposed to do it. If I'm wrong, someone correct me please.



#3. Don't think of it like that. Raising the temperature of a reaction is going to favor products when an endothermic reaction. When it's an exothermic reaction, adding heat would move it toward the reactants. This can easily be cleared up by looking up LeChatlier's principle on wiki.

#4 Increasing branching will increase melting point, but decrease boiling point.

Melting point is increased because it can fit into a crystal lattice better. However, due to branching, like the basic concept of boiling point, less intermolecular forces = easier to evaporate = decreases boiling point.

 

[DDSguyLA]

for #4:
because of the heat everything moves faster and hit each other at a faster rate therefore raising the rate of the reaction...

think of HOMER... LOL.. Desstroyer homer that is...

 

[whoaaitzkyle]

for #4:
because of the heat everything moves faster and hit each other at a faster rate therefore raising the rate of the reaction...

think of HOMER... LOL.. Desstroyer homer that is...

that analogy actually helps.

 

[dvduplex]

here are the answer:

1. 125ml
2. 1.66x10^-4

for #1, it took me forever to get the answer but this is how I think they did it.

(18-3)(25ml)= (V2)(3M)
V2= 125ml

I hope they don't have a questions like that on the test because it is kind of tricky.

thank you for your help whoaaitzkyle and DDSguyLA for your help.

now, Im trying to figure out how to do #2. So, if anyone know how to do it, feel free to post the solution to the answer.