Chemistry - January 2007

2H2(g) + O2(g) --> 2H2O(g) ΔH = −486.6kJ

a) A phase change is involved


b) Two moles of hydrogen gas react with one mole of oxygen gas to
produce two moles of liquid water


c) Energy is absorbed by the system, the reaction species


d) If the reaction takes place at constant pressure, q = −483.6 kJ


e) ΔH for reacting four moles of hydrogen gas with two moles of
of oxygen gas is −483.6 kJ

2007-01-26 08:29:16 · 4 answers · asked by simonkf2002 1

when 2.84 g of MgSO4 is dissolved in the water ?
For the following reaction to occur



MgSO4 → Mg2+(aq) + SO42−(aq)



the change in enthalpy must be −91.3 kJ/mol

2007-01-26 08:26:51 · 1 answers · asked by simonkf2002 1

2007-01-26 08:25:29 · 12 answers · asked by bruvvamoff 5

The specific heat capacity of solid water is 2.03 J g-1 oC -1


Use a negative sign in your answer if heat is removed.

2007-01-26 08:23:57 · 1 answers · asked by simonkf2002 1

calculate the molar solubility of Ag2CO3 in water. at 25C, ksp=8.1 x 10^ -12

2007-01-26 08:23:16 · 1 answers · asked by tmlfan 4

what is the chemical formula
for ammonium hydrogen sulfate

I need to enter it on a answer a chemistry woksheet

2007-01-26 07:59:38 · 3 answers · asked by Alison L 1

2007-01-26 07:56:18 · 4 answers · asked by .prc to .pdf 1

How many moles of atoms are present in 5 moles of Ca(HCO3)2 ?

2007-01-26 07:34:42 · 2 answers · asked by beachbum 2

I know about electronegativities of elements, but I don't know what they have to do with dipole moments. Also, why do some molecules have no dipole moments?

2007-01-26 07:10:32 · 2 answers · asked by cookiesrme 4

How many grams of nicotine (C10H14N2)contain 18.0 g H?

mass C10H14N2 = __________g

2007-01-26 07:05:59 · 2 answers · asked by beachbum 2

2007-01-26 06:56:17 · 6 answers · asked by .prc to .pdf 1

I need to know what the purpose is of checking the acidity of carbonyl compounds is, can anyone help?

2007-01-26 06:34:26 · 6 answers · asked by Anonymous

Thank you so much for any help!


20. Fermentation allows for the recycling of NAD+ and the production of ATP under____conditions.
21. In absence of oxygen, instead of aerobic respiration following glycolysis, glycolysis is followed by ______. 22. During fermentation, either ethyl alcohol and carbon dioxide or ___ is formed.
23. Because oxygen is the final electron acceptor at the end of the electron transport chain, if oxygen were absent in aerobic respiration, no _____ would be made.
24. Hydrogen ions combine with electrons and oxygen forming ____ at the end of the electron transport chain.

2007-01-26 06:33:36 · 3 answers · asked by Anonymous

chemical or physical change if the temperature of hot coffee drops upon the addition of some cold milk

2007-01-26 06:32:44 · 8 answers · asked by chelsey s 1

consider the following reaction.
H2 (g) 2CO(g) ---> H2O2(l) + 2C(s) DeltaH = +22.2kj

Calculate the enthalphy change when 5 moles of CO is consumed

2007-01-26 06:08:06 · 6 answers · asked by Anonymous

2007-01-26 06:01:59 · 5 answers · asked by Anonymous

Calculate the theoretical amount of CaCl2 that would be required to change the remperature of 50ml of water from room temperature 20-45 degrees celcius

In order to do this calculation you'll need the heat capacity of water (4.184Jg-1deg-1) You can assume that the density of water is 1g/mL
This question is based on the thermochemistry of hot packs!

** Can you please explain step by step how to solve this problem and give the solution as well

thanks

2007-01-26 05:47:24 · 2 answers · asked by CC 2

Phases of matter

2007-01-26 05:43:29 · 3 answers · asked by Anonymous

I'm not talking about having plants in your house. I got plenty of those. I'm talking about chemistry.

2007-01-26 05:23:19 · 4 answers · asked by Anonymous

4. [1pt]


2H2(g) + O2(g) --> 2H2O(g) ΔH = −486.6kJ



Which of the following are true statements for the above chemical reaction ?



a) A phase change is involved


b) Two moles of hydrogen gas react with two moles of oxygen gas to
produce two moles of water vapor


c) Energy is given off to the surroundings


d) If the reaction takes place at constant pressure, q = −483.6 kJ


e) ΔH for reacting one mole of hydrogen gas with a half mole of
of oxygen gas is −241.8 kJ





You must enter the letters you choose in one lower case group, with no spaces between.
Eg. if you choose a) d) and e) you would enter ade

2007-01-26 05:21:46 · 5 answers · asked by sunyrob 1

2007-01-26 04:54:22 · 5 answers · asked by smile 1

2007-01-26 04:50:12 · 1 answers · asked by ensar 1

How much heat (kJ) must be removed in order to change 3.70 moles of water at 62.0 oC to ice at -11.0 oC ?


The specific heat capacity of solid water is 2.03 J g-1 oC -1


Use a negative sign in your answer if heat is removed.

2007-01-26 04:40:50 · 2 answers · asked by Foxychick 1

2007-01-26 04:16:06 · 1 answers · asked by Wojciech K 1

2007-01-26 04:01:27 · 1 answers · asked by Anonymous

2007-01-26 03:55:55 · 15 answers · asked by gazwj 1

will the diamond melt? or burn, etc? will it be damaged?

2007-01-26 03:50:43 · 10 answers · asked by jiggawut25 1

CH3OCH3, its non-polar.... it has london, but what else forces are there?

2007-01-26 03:09:11 · 5 answers · asked by mike_online_now 3

for the reaction

CO+ NO2 = CO2+ NO

the activity energy for the forward reaction is 135 kj/mol of co recated.

what would be the heat reaction

2007-01-26 02:52:56 · 1 answers · asked by Hally berry 3

What would be the effect of an increase in temperature on the rate constant of :
a) The forward reaction
b) The reverse reaction?

2007-01-26 02:50:22 · 3 answers · asked by Hally berry 3