Chemistry - April 2007

Mg(s) + H1+(aq) Mg2+(aq) + H2(g)
(a) Select all that apply.
H1+ is the substance being oxidized.
Mg is the reducing agent.
H1+ is the substance being reduced.
Mg is the substance being reduced.
H1+ is the reducing agent.
Mg is the substance being oxidized.
H1+ is the oxidzing agent.
Mg is the oxidzing agent.


Type the following answers using the formats given. Use only the format '1+' or '1-' for the charge on an ion. If only one electron is present in the half-cell reaction, type the answer as e- instead of 1e-.

Half-cell Equation Au3+(aq) + 3 e- Au(s)
Typed Answer Au3+(aq) + 3e- > Au(s)

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Balanced Equation 2 Au3+(aq) + 3 Zn(s) 2 Au(s) + 3 Zn2+(aq)
Typed Answer 2Au3+(aq) + 3Zn(s) > 2Au(s) + 3Zn2+(aq)

(b) Write the half-cell reaction for the oxidation.

(c) Write the half-cell reaction for the reduction.

(d) Write the balanced equation for the cell reaction. Keep substances in the order given in the original equation.

2007-04-29 16:40:42 · 1 answers · asked by sakinah_123 1

2007-04-29 16:39:42 · 2 answers · asked by Haseeb K 1

The assignment is to predict the hydrolysis reaction equation for the following salt: Al(NO3)3
and this is what I came up with:
Al(NO3)3 + H2O --> Al(OH)3 + HNO3
is this correct and if so how do you balance this equation?
Thank you!

2007-04-29 16:23:58 · 4 answers · asked by Anonymous

2007-04-29 16:21:07 · 2 answers · asked by Haseeb K 1

1. Write the concentration of H3O+ ions as a decimal. Then translate the decimal into words?

2. At that concentration, how many individual H3O+ ions are there in one liter of solution?

3. Write out the numeral (with all zeros) your answer in #2 represents. Then write its name?

Thanks for any help you can give me.

2007-04-29 16:12:11 · 1 answers · asked by ~SMCM101~NYC 2

2007-04-29 16:00:42 · 2 answers · asked by purplemarcian 1

A 0.053g sample of Ca(OH)2 is dissolved in enough water to make 115mL of solution. Calculate the [H3O] and [OH] for this solution.

PLEASE include step-by-step instructions.

2007-04-29 15:48:37 · 1 answers · asked by ? 2

For 1.9 mole of the radioactive isotope chromium-51, half-life = 27.8 days, how many disintegrations have occurred after 17 minutes?

2007-04-29 15:21:44 · 3 answers · asked by twinriddim22 2

When 112 g of water at a temperature of 22.5°C is mixed with 65.1 g of water at an unknown temperature, the final temperature of the resulting mixture is 48.0°C. What was the initial temperature of the second sample of water?

2007-04-29 15:21:34 · 1 answers · asked by Anonymous

A 237 g piece of molybdenum, initially at 100.0°C, is dropped into 244 g of water at 10.0°C. When the system comes to thermal equilibrium, the temperature is 15.3°C. What is the specific heat capacity of molybdenum?

2007-04-29 15:20:14 · 1 answers · asked by Anonymous

For a first order reaction the rate R = −k N so the ratio of rates at two different times is given by R(t1)/R(t2) = N(t1)/N(t2).
For nuclear decay the rate is ofen is expressed in units of counts per unit of time.

A chemists determines that a sample of petrified wood is 5.00 X 103 years old. What is the rate of decay, in counts per minute per gram, of carbon-14 in the sample? The decay rate of carbon-14 in wood today is 13.6 counts per minute per gram, and the half life of carbon-14 is 5730 years.

Last Answer: 3.574079998e10
Incorrect, tries 2/10.

I am aware that I would use "equation ln(N/No) = -kt."
Though, I can't seem to be using it correctly...plz help!

2007-04-29 15:15:15 · 1 answers · asked by L 2

2007-04-29 15:13:30 · 2 answers · asked by chamiqua42 1

calculate the molar Enthalpy change of the reaction between hydrochloric acid and ammonia

2007-04-29 15:12:10 · 1 answers · asked by scoota 1

How long (in days) will it take for 52.0% of a 0.00890 mg sample of radioactive iodine-131 to decay? The half-life of iodine-131 is 8.10 days.

2007-04-29 15:10:03 · 1 answers · asked by Anonymous

2007-04-29 15:09:45 · 1 answers · asked by scoota 1

2007-04-29 15:09:14 · 1 answers · asked by scoota 1

in kJ/mol if 5 moles of HA neutralized 3.31 moles of BOH and released 12,000 J of heat?

2007-04-29 15:08:21 · 1 answers · asked by scoota 1

(A) OH^- , SO4^2- , HSO4^- , H3O^+
(B) OH^- , H3O^+ , SO4^2- , HSO4^-
(C) H3O^+ , SO4^2- , OH^- , HSO4^-
(D) H3O^+ , HSO4^- , SO4^2- , OH^-
(E) SO4^2- , OH^- , H3O^+ , HSO4^-

2007-04-29 15:03:20 · 2 answers · asked by Anonymous

I quickly need to know if a higher density will freeze quicker or slower than a lower one. If it is possible, list these in order from quickest freezing time to slowest freezing time.

Tap Water
Salt Water
Sugar Water
Vegetable Oil

2007-04-29 14:55:39 · 1 answers · asked by Anonymous

if you used metal with a specific heat twice that of silver, leaving everything else the same, what would the change in temperature of the water be?

If you used silver with half the mass leaving everything else the same, what would the change in temperature of the water be?

2007-04-29 14:52:36 · 2 answers · asked by Anonymous

like NaCl and stuff like that then the formula of sulfide oxide and etc.

2007-04-29 14:46:39 · 2 answers · asked by me duh 2

A sample of Nitrogen gas is collected over water at temperature of 23 degrees cekcius. What is the pressure of the nitrogen gas if the atmospheric pressure is 785 mmHg?

Steps please. Thanks :)

2007-04-29 14:45:49 · 1 answers · asked by kickitup21 1

A. Ca++, OH-
B. Ca++, 2OH-
C. 2Ca++, OH-
D. 2Ca++, 2OH-
E. 3Ca++, OH-

Please explain why.

2007-04-29 14:14:40 · 1 answers · asked by chemistrychicka 1

The isotope 228-Ra has a half life of 1602 years. How long would it take a sample of this isotope to decay to just 70.63% of its original activity? Answer in years Error tolerance: ±1%


A radioactive isotope has an initial decay rate of 43.71 dps (disintegrations per second) for a sample. After an elapsed time of 55.81 days, the rate has decreased to 17.78 dps. What is the half-life (in days) of this isotope? Error tolerance: ±1%

2007-04-29 14:13:43 · 1 answers · asked by Anonymous

From the info. shown here fill in the blanks
expt. rate(m/S) [a] [b]
1 0.24 0.20m 0.050m
2 0.20 ____m 0.030m
3 0.80 0.40m ____m

2007-04-29 13:59:03 · 1 answers · asked by random Q 2

To prepare anatase TiO2, I have neutralized aqueous Titanium sulphate solution to 4M sodium hydroxide solution, gradually blue tint and finally milk-white sol observed.

Often reported that, milk-white sol or slurry observed but no explanation for that. Could you explain the reason for milk-white colour why?

2007-04-29 13:51:38 · 1 answers · asked by vel m 1

If a 8.30 lb cat absorbs 3.30 × 10−5 KJ of radiation, how many rads did this cat absorb?

2007-04-29 13:50:22 · 2 answers · asked by dandevita 1

If a 3.30 lb cat absorbs 1.40 × 10−5 KJ of radiation, how many rads did this cat absorb?

2007-04-29 13:43:40 · 1 answers · asked by Anonymous

If a 8.30 lb cat absorbs 3.30 × 10−5 KJ of radiation, how many rads did this cat absorb?

2007-04-29 13:26:54 · 1 answers · asked by dandevita 1

Explain why the standard entropy of 1 mole of liquid methane (CH4) at its boiling point should be higher than the strandard entropy of 1 mole of liquid ammonia (NH3) at it's boiling point. Contrast this with the comparison between methane and ammonia gases.

2007-04-29 13:24:40 · 2 answers · asked by Robert W 1