Chemistry - April 2007

a) HNO3


b) Na


c) Br2


d) Cu


e) C

2007-04-23 14:57:42 · 1 answers · asked by auriclistens 1

Which of the following statements are true?


For statements a) through d) use the reaction:


SiCl4(l) + 2Mg(s) --> 2MgCl2(s) + Si(s)



a) Mg is the reducing agent

b) SiCl4 is the reducing agent

c) Mg is oxidized

d) SiCl4 (or Si in SiCl4) is oxidized

e) Zn(s) + 2HCl(aq) --> ZnCl2(aq) + H2(g) is a redox reaction

f) O3(g)(aq) + NO(g) --> O2(g) + NO2(g) is a redox reaction

2007-04-23 14:56:56 · 1 answers · asked by auriclistens 1

Rewrite the following word equations as formula equations and then balance them please.

a)solid sodium metal reacts with chlorine gas to produce solid sodium chloride

b)solid potassium metal reacts with oxygen gas to produce solid potassium oxide

c)aqueous cobalt(III) nitrate reacts with solid zinc to produce aqueous zinc nitrate and solid cobalt

d) aqueous sodium sulfate reacts with aqueous strontium hydroxide to produce aqueous sodium hydroxide and solid strontium sulfate

2007-04-23 14:56:29 · 5 answers · asked by Anonymous

Define a solution equilibrium, the word exothermic and endothermic and i will b able to answer one question.

and i don't get this question at all, it says the diffrence between a solution, a suspension and a colloid is only the size of the particles. A solution has the smallest particles and a colloid has the largest particles. When you shine a light through a colloid the light scatters, this is called the tyndell effect. When a cars geadlight beam scatters light on a foggy night it shows that foggy air is a colloid.

a.) identify the solute and the solvent?

b.) explain how the foggy air is a colloid

if you find that im just getting the answers, im not because i just need help with it so i can undestand. =]

2007-04-23 14:54:08 · 1 answers · asked by babishbluestar 1

help, ty free pointS!!

2007-04-23 14:50:51 · 2 answers · asked by Anonymous

the pH is observed to be 1.35. The Ka of propionic acid is?

2007-04-23 14:48:48 · 1 answers · asked by Kayla H 1

The specific heat of a 3.0 gram sample of a substance is


How much heat is needed to change the temperature from 22 to 60

205 J
342 J
11880 J

2007-04-23 14:48:06 · 1 answers · asked by Joe 3

1. When someone is standing at one end of a large rooms opens a bottle of vinegar, it may take several mintues for a person at the other end to smell it. Gas molecules at room temperature move at very high velocities, so what is responsible for the delay in detection of the vinegar?

2. Standard temp. and pressure (STP) are defined as what?

3. If the solubility of NaCl at 25 degrees celcius is 36.2/100g H2O, what mass of NaCl can be dissolved in 50. g of H2O?

4. How many moles of HNO3 are needed to prepare 5.0 liters of a 2.0 M solution of NHO3?

5. The random molecular motion of a substance is greated when the substance is

A. Condensed
B. A liquid
C. Frozen
D. a gas

6. The Specific heat of copper is about 0.4 joules/gram degrees celsius. How much is needed to change the temperature of a 30-gram sample of copper from 20.0 degrees celsius to 60.0 degrees celsius?

7.When a reaction is at equilibrium and more reactant is added, which of the following changes is the immediate result?

2007-04-23 14:45:45 · 1 answers · asked by Rose S 2

I need to know the overall chemical reactions between the following:
Zinc and Copper (II) Sulfate
Lead and Copper (II) Sulfate
Zinc and Lead (II) nitrate

Thank you in advance for your help!

2007-04-23 14:43:31 · 1 answers · asked by calculusgirl1979 2

how many grams of KCl are produced from the complete reaction of 6.60 mol of KClO?
How many grams of KCl are produced from the complete reaction of 47.5g of KClO3 ?

2007-04-23 14:39:24 · 1 answers · asked by momcreynolds 1

produce a solution with pH=2.5?

2007-04-23 14:35:19 · 1 answers · asked by Kayla H 1

2007-04-23 14:33:20 · 1 answers · asked by Kayla H 1

It has to be an element

2007-04-23 14:31:09 · 3 answers · asked by Anonymous

of the NH3 is 1.2 atm. What is the equilibrium constant for this reaction? NH4Cl---->NH2 + HCl

2007-04-23 14:29:09 · 2 answers · asked by Kayla H 1

im kinda stuck on these two problems, this first was says:

1.) Using the phases of matter, list possible types of solutions and give one example of each. I got one example and its gas/liquid solution and an example is soda, i can't think of anything else

2007-04-23 14:23:06 · 1 answers · asked by babishbluestar 1

A) it gains electrons when it becomes an ion
B) It has to same atomic mass
C) It reacts with Magnesium
D) It has the same number of protons

2007-04-23 14:12:50 · 6 answers · asked by IDchecker27 2

Air from the prairies of North Dakota inwinter contains essentially only nitrogen, oxygen, and argon. A sample of air collected a Bismark at -22 degrees celcius and 98.90 kPa had 78% N2, 21% O2 and 1% Ar. Find the parcial pressures for each gas.

Steps please.

2007-04-23 14:07:46 · 2 answers · asked by kickitup21 1

what is this?

2007-04-23 13:57:02 · 2 answers · asked by a d 3

When chemists compare rates of reactions carried out under different conditions they often compare rates near the beginning of the reaction. What advantage does this offer?

2007-04-23 13:49:03 · 2 answers · asked by Anonymous

For a given set of data, two students determined different average reaction rates. If neither student made an error in the calculations, account for the different in their reaction rates.

2007-04-23 13:41:53 · 1 answers · asked by Anonymous

2007-04-23 13:40:29 · 3 answers · asked by Anonymous

Cookie Sample Tortilla
Weight of Sample (g) 1.021
Weight of Water Used (g) 100
Initial Temperature of Water (°C) 22.3
Final Temperature of Water (°C) 72.0

Calculate the change in temperature of the water.
Calculate the heat released by the food and absorbed by the water
Calculate the joules released per gram of food burned.

I don't know how to calculate these, so if you could please show me the work and any formulas if necessary. Thanks.

2007-04-23 13:39:32 · 1 answers · asked by Anonymous

2007-04-23 13:33:39 · 5 answers · asked by zman29301 1

2007-04-23 13:32:03 · 1 answers · asked by jsch18z 1

I forgot my science book today at school

2007-04-23 13:16:03 · 1 answers · asked by Roxxie B 1

2007-04-23 13:13:56 · 1 answers · asked by anonymous91 1

2007-04-23 13:05:17 · 1 answers · asked by Matt B 1

I need to know how many number of neutrons element 114 has. I need a picture of the element 114 on the Lewis Electron Dot Diagram.

2007-04-23 12:39:22 · 3 answers · asked by Dixie J 1

1. What is the neautralization reaction for HNO3 and NH4OH?
2. And for HC2H3O2 and KOH?

Either one, please?
I am confused how to go about doing these. Thanks so much!

2007-04-23 12:37:48 · 2 answers · asked by :] 3

if you hold a magnet above it will it be attracted/

2007-04-23 12:33:36 · 2 answers · asked by andrew 3