Chemistry - May 2007

molten ionic compounds are used to store heat. how many kj of energy are released when 8.37 kg of NaCl solidifies at its melting point?

giving: 519 J/g heat fusion and 13,100 vaporization

2007-05-07 21:15:18 · 1 answers · asked by kevin 1

what wil be the final temperature of the water? c water = 4.18 J / g °C:
and how are you coming to that conclusion
my answer does not look right to me

2007-05-07 21:13:40 · 3 answers · asked by Anthony L 1

Okay my science project was basically using chromatography to separates 6 inks: red, yellow, blue and orange, green and purple. My hypothesis was that red, yellow and blue [primary colours] would be made up of themselves and that orange, green and purple [secondary colours] would consist of their respective primary colours e.g. orange would be made up of red and yellow.

However, the red turned sort of pinkish, the orange was made of pink and yellow and the purple was made of blue and pink.
So the reds kind of turned out pink...

So, what should the conclusion of my experiment be? And for the orange, the dye was definitely pink, and did not turn pink just because the water diluted it...

2007-05-07 21:12:14 · 4 answers · asked by MissUnderstood 3

a) An alloy is a material made of two or more metals mixed together. Brass and bronze are alloys. Which two metals make up the alloys brass and bronze?
Brass:
Bronze:

b) Why is brass better than copper for pins of electricity lugs?

c) What is a mixture of tin and lead commonly used for?

d) Why is copper better than aluminium for cables?

e) Why do aluminium cables have strands of steel in them?

2007-05-07 20:59:51 · 2 answers · asked by Anonymous

Beryllium
1.82

Copper
.385

Gasoline
2.22

Diamond
.509

2007-05-07 20:58:26 · 5 answers · asked by Charlie 1

2007-05-07 20:55:59 · 2 answers · asked by Charlie 1

2007-05-07 20:41:10 · 1 answers · asked by akma w 1

please help me the quick determine formol in food, such as quick stick test ( how to make this quick stick??? and how to determine formol in lab ) thank a lot

2007-05-07 20:34:25 · 1 answers · asked by Nguyen Huan 1

2007-05-07 20:16:43 · 3 answers · asked by Anonymous

Normal melting point: 658 C
Normal boiling point: 2467 C
Heat fusion: 3.95 Kj/g
Heat of vaporization: 10.52 KJ/g
Specific heat of solid: 0.902 J/G C

How many energy must be applied to 12 moles of solid aluminum a 72 C to a liquid at 658 C?

2007-05-07 20:16:11 · 1 answers · asked by kevin 1

Cl + O3 -> ClO + O2
ClO + O3-> Cl +2O2

2007-05-07 20:14:52 · 2 answers · asked by Anonymous

2007-05-07 19:53:23 · 7 answers · asked by simonaaa <3 1

2007-05-07 19:27:59 · 2 answers · asked by pooja P 1

2007-05-07 19:22:48 · 1 answers · asked by gary 1

Give a scientific reason why do you think this is so

2007-05-07 18:56:08 · 4 answers · asked by bballchic601 1

2007-05-07 18:35:28 · 1 answers · asked by tim_childress 1

2007-05-07 18:31:04 · 1 answers · asked by kander0101 1

would it be considered endo or exo-thermic???

2007-05-07 18:27:35 · 1 answers · asked by Charlie 1

The molar heat of fusion of benzene is 9.92 kJ/mol. Its molar heat of vaporization is 30.7 kJ/mol. Calculate the heat required to melt 8.01 g of benzene at its normal melting point.
kJ
Calculate the heat required to vaporize 8.01 g of benzene at its normal boiling point
kJ
Why is the heat of vaporization more than three times the heat of fusion?

2007-05-07 18:23:41 · 1 answers · asked by Anonymous

The molar heats of fusion and vaporization for water are 6.02 kJ/mol and 40.6 kJ/mol, respectively, and the specific heat capacity of liquid water is 4.18 J/g°C.
(a) What quantity of heat energy is required to melt 23.0 g of ice at 0°C?
kJ
(b) What quantity of heat is required to vaporize 34.5 of liquid water at 100°C?
kJ
(c) What quantity of heat is required to warm 53.9 g of liquid water from 0°C to 100°C?
kJ

2007-05-07 18:20:54 · 1 answers · asked by Anonymous

Some properties of aluminum are summarized in the following list.


normal melting point 658°C
heat of fusion 3.95 kJ/g
normal boiling point 2467°C
heat of vaporization 10.52 kJ/g
specific heat of the solid 0.902 J/g°C

(a) Calculate the quantity of energy required to heat 1.00 mol of aluminum from 25°C to its normal melting point.
kJ
(b) Calculate the quantity of energy required to melt 2.00 mol of aluminum at 658°C.
kJ
(c) Calculate the amount of energy required to vaporize 1.00 mol of aluminum at 2467°C.
kJ

2007-05-07 18:19:57 · 1 answers · asked by Anonymous

Which substance in each pair would be expected to show the largest vapor pressure at a given temperature?
(a) H2O(l) or HF(l)
HF
H2O
Explain your reasoning.

2007-05-07 18:18:58 · 1 answers · asked by Anonymous

Which type of forces (intramolecular or intermolecular) must be overcome to melt a solid or vaporize a liquid?
intermolecular
intramolecular
Explain.

2007-05-07 18:18:11 · 2 answers · asked by Anonymous

Which substance in each pair would be expected to show the largest vapor pressure at a given temperature?
(a) H2O(l) or HF(l)
HF
H2O
Explain your reasoning.

(b) CH3OCH3(l) or CH3CH2OH(l)
CH3CH2OH
CH3OCH3
Explain your reasoning.

(c) CH3OH(l) or CH3SH(l)
CH3OH
CH3SH
Explain your reasoning.

2007-05-07 18:16:04 · 1 answers · asked by Anonymous

The molar heats of fusion and vaporization for water are 6.02 kJ/mol and 40.6 kJ/mol, respectively, and the specific heat capacity of liquid water is 4.18 J/g°C.
(a) What quantity of heat energy is required to melt 23.0 g of ice at 0°C?
kJ
(b) What quantity of heat is required to vaporize 34.5 of liquid water at 100°C?
kJ
(c) What quantity of heat is required to warm 53.9 g of liquid water from 0°C to 100°C?
kJ

2007-05-07 18:13:50 · 1 answers · asked by Anonymous

1. The velocity of the flow of the carrier gas diminishes: Does the retention time increases, diminishes or stays the same?

2. The temperature of the column increases: Does the retention time increases, diminishes or stays the same?

3. The length of the column increases: Does the retention time increases, diminishes or stays the same?

Please help, guys. Thanks in advance

2007-05-07 17:41:28 · 2 answers · asked by some guy 1

A gaseous mixture containing 1.5 moles of Ar and 3.5 moles of CO2 has a total pressure of 7.0 atm. What is the partial pressure of CO2?

2007-05-07 17:36:50 · 1 answers · asked by Chem Rookie 1

What is the molecular geometry of hydrogen sulfide?
What is the electron geometry of xenon tetrafluoride?
What are two possible locations for the lone pairs in xenon tetrafluoride?
Which of these configurations is most favorable
What is the molecular geometry of xenon tetrafluoride?
Draw the lewis structure of the triiodide ion?
What is the electron geometry of the central iodine atom?
What is the molecular triiodide ion

2007-05-07 17:29:12 · 1 answers · asked by Anonymous

Okay this is all the info I know Wavelength= 5.0 m amplitude=1.5m time interval=1 second
How do I find the velocity? (Also wat is energy Rank mean)

2007-05-07 16:45:16 · 3 answers · asked by Anonymous

2007-05-07 16:38:27 · 1 answers · asked by Rachael M 1