Chemistry - May 2007

A. completely

B. partially

2007-05-31 05:12:27 · 3 answers · asked by Anonymous

A. Alkalis
B. Electrolytes

2007-05-31 05:11:30 · 4 answers · asked by Anonymous

2007-05-31 05:10:25 · 4 answers · asked by kimprof2001 1

Acid or Base?????

2007-05-31 05:09:56 · 6 answers · asked by Anonymous

A. acid

B. base

2007-05-31 05:09:27 · 5 answers · asked by Anonymous

Which of the following types of energy is a form of potential energy?

a.gravitational energy
b.thermal energy
c.sound energy
d.mechanical energy
e.electrical energy

2007-05-31 04:54:43 · 7 answers · asked by kallystarr 1

Calculate ΔE for the system in which 16 J of work is done on a gas by the surroundings and the gas absorbs 51 J of heat?

a.+51 J
b.+35 J
c.+67 J
d.-35 J
e.-67 J

2007-05-31 04:54:17 · 1 answers · asked by kallystarr 1

What is the concentration, in moles per liter, when 1.5g NaI is dissolved in 250-mL solution of NaI (at. wts: Na=23.0, I=126.9)

2007-05-31 04:48:58 · 3 answers · asked by Anonymous

If 50.0 g H2O at 13.6 °C is combined with 85.0 g H2O at 93.7 °C, what is the final temperature of the mixture? The specific heat capacity of water is 4.184 J/g·K.

a.56.1 °C
b.80.1 °C
c.26.1 °C
d.40.0 °C
e.64.0 °C

2007-05-31 04:48:29 · 1 answers · asked by Anonymous

Determine the heat of reaction for the oxidation of iron,
4 Fe(s) + 3 O2(g) → 2 Fe2O3(s)
given the thermochemical equations below.

2 Fe(s) + 6 H2O(λ) → 2 Fe(OH)3(s) + 3 H2(g) ΔH = +321.8 kJ
2 H2O(λ) → 2 H2(g) + O2(g) ΔH = +571.7 kJ
Fe2O3(s) + 3 H2O(λ) → 2 Fe(OH)3(s) ΔH = +288.6 kJ

a.-505.3 kJ
b.+360.5 kJ
c.-1182.1 kJ
d.+1447.1 kJ
e.-1648.7 kJ

2007-05-31 04:48:20 · 1 answers · asked by Anonymous

Specific heat capacity is

a.the temperature change undergone when 1.00 g of a substance absorbs 4.184 J.

b.
the mass of a substance that 1.00 cal of energy will heat by 1.00 K.

c.the quantity of heat needed to change 1.00 g of a substance by 1.00 K.

d.the quantity of heat required to melt 4.184 g of a substance.

e.the mass of a substance that 1.00 J of energy will heat by 1.00 K.

2007-05-31 04:47:27 · 2 answers · asked by Anonymous

A chemical reaction in a bomb calorimeter evolves 5.17 kJ of heat. If the heat capacity of the calorimeter is 1.08 kJ/°C, what is the temperature change of the calorimeter?

a.4.09 °C
b.0.209 °C
c.5.58 °C
d.4.79 °C
e.6.25 °C

2007-05-31 04:44:52 · 1 answers · asked by Anonymous

If 1.86 g MgO is combined with 100.0 mL of 1.00 M HCl (density 100.0 g/mL) in a coffee cup calorimeter, the temperature of the resulting solution increases from 21.3 °C to 35.7 °C. Calculate the enthalpy change for the reaction per mole of MgO. Assume that the specific heat capacity of the solution is 4.18 J/g·K.

a.-28.3 kJ
b.-6.13 kJ
c.-613 kJ
d.-133 kJ
e.-329 kJ

2007-05-31 04:44:39 · 2 answers · asked by Anonymous

Calculate the amount of heat required to change 50.0 g ice at -20.0 °C to steam at 135 °C. (Heat of fusion = 333 J/g; heat of vaporization = 2260 J/g; specific heat capacities: ice = 2.09 J/g·K, liquid water = 4.18 J/g·K, steam = 1.84 J/g·K)

a.32.4 kJ
b.135 kJ
c.156 kJ
d.78.8 kJ
e.4.18 kJ

2007-05-31 04:41:29 · 1 answers · asked by Anonymous

If 136 J is required to change the temperature of 8.75 g of nickel by 35.0 K, what is the specific heat capacity of mercury?

a.0.0294 J/g·K
b.2.25 J/g·K
c.0.444 J/g·K
d.0.311 J/g·K
e.0.417 J/g·K

2007-05-31 04:40:25 · 3 answers · asked by Anonymous

If 46.1 g Zn at 18.0 °C is placed in 80.0 g H2O at 75.0 °C, what is the final temperature of the mixture? The specific heat capacities of zinc and water are 0.388 J/g·K and 4.184 J/g·K, respectively.

a.64.5 °C
b.27.3 °C
c.72.1 °C
d.65.7 °C
e.20.9 °C

2007-05-31 04:40:11 · 1 answers · asked by Anonymous

Hydrazine, N2H4, is a liquid used as a rocket fuel. It reacts with oxygen to yield nitrogen gas and water.

N2H4(λ) + O2(g) → N2(g) + 2 H2O(λ)

The reaction of 3.80 g N2H4 evolves 73.7 kJ of heat. Calculate the enthalpy change per mole of hydrazine combusted.

a.-8.98 × 103 kJ/mol
b.-622 kJ/mol
c.-8.74 kJ/mol
d.-19.4 kJ/mol
e.-2.80 × 102 kJ/mol

2007-05-31 04:32:08 · 2 answers · asked by Anonymous

A 2.885 g sample of methanol, CH3OH, is combusted in a bomb calorimeter. The temperature of the calorimeter increases by 11.38 K. If the heat capacity of the bomb is 727.1 J/K and it contains 1.200 kg of water, what is the heat evolved per mole of methanol combusted? The specific heat capacity of water is 4.184 J/g·K and the molar mass of methanol is 32.04 g/mol.

a.-726.5 kJ/mol
b.-634.5 kJ/mol
c.-91.89 kJ/mol
d.-1.019 × 106 kJ/mol
e.-65.41 kJ/mol

2007-05-31 04:32:04 · 3 answers · asked by Anonymous

Chemistry

2007-05-31 04:25:53 · 6 answers · asked by babydollnaynay 1

2007-05-31 03:53:47 · 1 answers · asked by Sarah G 2

give two examples of aromatic waters where talc is used

2007-05-31 03:42:49 · 1 answers · asked by jdksydney 2

2007-05-31 03:35:19 · 3 answers · asked by gauravadi 1

How many equivalents are in the following masses?

a. 42.3g of HNO3

b. 10.5g of Al(OH)3

c. 5.4g of Ca(OH)2

I don't just want the answers I would like to know how to do it too, I know I'm a dork but I want to learn! lol

2007-05-31 03:28:36 · 1 answers · asked by ♥chloe♥ 2

What will be the volume, at 115 kPa and 355K, of the nitrogen from decomposition of 35.8 g of sodium azide, NaN3? 2NaN3 -> 2Na + 3N2

2007-05-31 03:27:01 · 2 answers · asked by violenta10906 1

How many moles of SO2 gas are contained in a 4.0 L container at 450K and 5.0 kPa?

2007-05-31 03:25:32 · 2 answers · asked by violenta10906 1

2007-05-31 03:24:16 · 2 answers · asked by kp 3

A sample of carbon dioxide has a mass of 35.0 g and occupies 2.5 L at 400.0K. What pressure does the gas exert?

2007-05-31 03:23:14 · 3 answers · asked by <3 1

How many moles of argon are there in 20.0L, at 25oC and 96.8 kPa?

2007-05-31 03:22:22 · 2 answers · asked by <3 1

How does the total pressure of a mixture of gases relate to the partial pressures of the individual gases in a mixture?

2007-05-31 03:21:51 · 1 answers · asked by <3 1

keeping 100 g of a comound form absorbing atmospheric moisture

mixing two liquids together

keeping the contents of a boiling beaker from splatterig

removing chemicals from a reagent bottle

2007-05-31 02:53:58 · 3 answers · asked by Anonymous