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State the null and alternative hypotheses.
Some previous studies found that college students averaged 8 hours or so per week on the internet. With more people owning cell phones we think that...

a.do you live on campus?
I think this one is quantitative variable

b.how tall are you?
I think this one is categorical variable

c.favorite color of the rainbow?
I think this one is...

So, I think number 3 is going to be
2H2 + Ag^+ ------------------------> 2H^+ + Ag

Thanks!

standardization of KMnO4
Mass of H2C2O4.2H2O(MW=126g/mol),g------->0.25
Initial buret reading, mL-------------------------->0
Final buret reading, mL--------------------------->43
Volume of KMnO4...

1) Mg+N2---->Mg3N2
3Mg+N2----->Mg3N2
I really don't know how to do this one..

2) Cu^2+ + Al----->Cu+Al^3+
2e+Cu^2+ ----> Cu X3
Al------>Al^3+ + 3e X2
6e+3Cu^2+ -----> 3Cu
2Al----->2Al^3...

Do you know any formula for this problem?

Thanks

Thank you!!

Can you help me on this..
A piece of a metal 34.9g was heated to about 95C and them added to 550g water with the initial temperature of 28.2C. If the final temperature of the water...

Cl is -1
I hope it is!

So, S is +1?
Thanks

ohh okay Thanks^^

A piece of a metal (34.9g) was heated to about 95C and then added to 550g water with the initial temperature of 28.2C. If the final temperature of the water and the metal is 31.2C, calculate the...

S in K2S4O6
If K is +1 and O is -2

+2 + -12 = -10

but that's S4.. so... It should be +2 or +3... I guess...
and Cl in HCl is +1

Thank

So, this answer going to be 574.08J

Correct?

Thanks

Calculate the quantity of heat lost when 52g of S is cooled from 85C to 60C.
The specific heat of sulfur is 0.736J/g C.

Do I have to find mole of S first?

Please help the step to solve this...

Mn in MnCl2 --> +2
Mn in MnO4^- ----> +7
S in K2S4O6 ----------> +13
Cl in HCl ------>+1

are these are correct?
but I cannot find Mn in MnO4^- this part on equation...

THanks

Thanks~~
how about this one?
Fe^2+ + Cr2O7^2- -------------> Fe^3+ + Cr^3+
I did it...
6Fe^2+ + Cr2O7^2- + 14H^+ -------------> 6Fe^3+ + 2Cr^3+ + 7H2O
I hope it is corret..

when...

2KMnO_4\ + 10K_2S_2O_3 + 16HCl \rightarrow 2MnCl_2 + 5K_2S_4O_6 + 12KCl + 8H_2O

what is the oxidation number of

Mn in MnCl2 --> +2
Mn in MnO4^- ---->
S in K2S4O6 ----------> +10
Cl...

write the balanced chemical equation for the reaction of Fe2+ with MnO4- in acidic solution.

I did it , but I am not sure. Please check it for me

H^+ + MnO4^- + Fe2+ ---------------> Mn2+ +...

a)△H for the reaction of NaOH and HCl solutions will be the same as △H for reaction of KOH and HNO3 solutions because the net ionic equation is the same in each case.

b)△H for the reaction of NaOH...

So heat absorbed by the calorimeter is 1046J
correct?
heat dissipated to calorimeter = 5020.8 - 3974.8 =1046 J
And how can I find Q is the amount of energy
Theta is the change in temperature of...

Temperature of colder water : 23C
Temperature of warmer water : 66C
Final temp of water after mixing : 42C
Heat lost by the warmer water : -5020.8J ,(209.2)(42-66)
Heat gained by colder water :...

If the final temperature for above were 34.7ºC
a)how much heat was lost to the calorimeter?
b)calculate heat capacity
c)for the calorimeter.

so, a) is 37.3-34.7=2.6?

I don't know how to get...

I got 37.3ºC

So,
these 3 quesetions answers are

Al^{3+} + 3 OH^- \rightarrow Al(OH)_3
Fe^{3+} + 3 OH^- \rightarrow Fe(OH)_3
Ni^{2+} + 2 OH^- \rightarrow Ni(OH)_2

Yes I got that number thanks

Could please help me how to find this one?

4.what is the mass of excess reagent?

I really don't understand so just number 1 answer is
Al^{3+} + 3 OH^- \rightarrow Al(OH)_3[/QUOTE]

this?

I don't understand sorry,

So mass of aluminum sulfide formed is 29.4g?

A 56.3g of water was heated to 51.2C and added to 45.8g of 20.3C water in a calorimeter.
Assume that no heat was lost to the surroundings; calculatee the final temp. of the resulting solution.

I...

To make a cup of coffee, you heated 0.175kg of water to change the water temperature from 23.OC to 89.0C . Calculate the quantity of heat(J) required.

(175g)(4.18J/g)(89-23)=48279J

I did...

write the net ionic equations for the reactions which occurred when aqueous KOH was initially added to:

1)Al(NO3)3 : I think this one is souble equation.

2)Fe(NO3)3 : Fe^3+ + 3OH^- ---->...

1.what is the mass of aluminum sulfide formed?
So, its just adding 4.5g and 6.8g? So its 11.3g??

Yes 0.040moles is correct >.<

On my book, it says only like" what are concentrations of species in 0.04M sodium sulfate in water? " this.. So that's why I was confusing..

So answer is just like 0.04mol/L and 0.04mol/1000mL , these?

Yes , so answer is 17.5g right?

Thanks

3.58g/1g x 100% = 358%?

If the concentration of NaCl is 0.25M, calculate
a.how many moles of NaCl there are in 20mL of the solution
0.005mol
b.what volume of the NaCl must be taken to contain 0.1mol of NaCl.
0.4L

Are...

Ohh that way is much easy!

Thanks

If a salt has solubility of 27.2g/100g water at 25ºC, what voulme of water would be needed to dissolve 12.4g of the salt.

Do you know any volume formula...

ohhh yes you are right I put 24mole instead of 2.4M

I got 0.0408moles of KOH

Finally I got 0.01335 equivalents of Al and 0.0204 equivalents of KOH.

So, it means Al is limithing reagent...
...

So.. KOH mole is .408mole?

:eek:

Al=(.72g)(1mol/26.98g)=0.0267moles

How can I find mole of KOH?

(1L)(1.25mol/0.35L)(40g/1mol)=142.86g

I really hope This is corret :p:confused::eek:

Is it correct?

Thank you~!~!~

A sample of 0.72g of Al is reacted with 17mL 2.4M KOH. Which one is the limiting reagent?

2Al+2KOH+6H2O------------->2KAl(OH)4+3H2

I don't know how to find limiting reagent on this case.. I...

A sample of 4.5g aluminum reacts with 6.8g of sulfur to form aluminum sulfide according to the following reaction.

2Al+3S----->Al2S3

Which one is the limiting reagent?
Al is limiting reagent....

I cannot see that cuase It error to opened

Its not homework, but I really want to know..

Why are the scientific terms “Caucasian, Negroid, and Mongoloid” harmful and misleading

Yes its perfectly balanced!

Thanks

40mole/1000mL=0.04M

?

so 0.040mol/1L=0.04M
0.040mol/1000mL=0.00004M

write a balanced reaction between Ba(OH)2 and H2SO4.
----> Ba(OH)2(aq) + H2SO4(aq) => BaSO4(s) + 2H2O(l)

So, this equation is correct?


Thanks for your explain