Chemistry - April 2007

This was a question out of a chemistry quiz:

When 5.37 g of black copper(II) oxide are mixed with excess sulfuric acid, the solution turns a clear blue, indicating the formation of copper(II) sulfate. How many grams of copper(II) sulphate will be formed in this double displacement reaction?

Further questions:

What exactly is copper (II)?
I don't understand the designation.

Also, what is black copper oxide?

2007-04-30 23:54:07 · 1 answers · asked by The Hammer 2

The following are the answers out of the book.
a. .30 M H2CO3
b. .20 M HCl
c. .50 M HCOOH
d. 1.0 M NH3

What i need to know is why they are choosing .20 HCl as the answer.

2007-04-30 23:51:16 · 1 answers · asked by Toothie 2

2007-04-30 23:44:08 · 2 answers · asked by babymae29x 1

2007-04-30 22:46:59 · 1 answers · asked by lonny o 1

1.How many grams of water will be produced from 50 g of hydrogen and 100 g of oxygen?

2. Equation given: 4Na+O2->2Na2O
If you have 100 g of sodium and 60 g of oxygen

A. Find the number of moles of sodium oxide produced.

B. Find the mass of excess reactant left over at the conclusion of the reaction.

2007-04-30 21:15:51 · 3 answers · asked by Joesph P 1

http://www.mp-docker.demon.co.uk/as_a2/topics/reactions_schemes_bromoethane/quiz_3.html

2007-04-30 21:04:10 · 2 answers · asked by Anonymous

please help!
correct me if im wrong

2007-04-30 20:34:56 · 7 answers · asked by Alfie_mcg 1

Carbon monoxide can be combined with hydrogen to produce methanol, CH3OH. Methanol is used as an industrial solvent, as a reactant in some synthesis reactions, and as a clean-burning fuel for some racing cars. If you had 152.5kg of carbon monoxide and 24.5kg of hydrogen gas, how many kilograms of methanol could be produced?

2007-04-30 20:23:05 · 2 answers · asked by Joesph P 1

Equation given: 2N2H4+N2O4 -> 3N2+ 4H2O
If u begin with 400 g of N2H4 and 900 g of N2O4..

A. Find the number of grams of water produced, assuming the reaction goes to completion.

B. Find the number of moles of nitrogen produced, assuming the reaction goes to completion.

C. Find the mass of excess reactant left over at the conclusion of the reaction.

2007-04-30 20:20:42 · 4 answers · asked by Joesph P 1

A 30.0 L tank contains 5.79 kg of N2 and 4.59 kg of O2. What is the pressure in the tank at 25°C?

2007-04-30 20:14:58 · 3 answers · asked by Anonymous

Question: In acidic solution, O3 and Mn2+ ion react spontaneously:

O3(g) + Mn2+ + H2O(l) ------> O2(g) + MnO2(s) + 2H+

Write the balanced half-reactions

My Approach:
I got Oxidation: 2H2O + Mn2+ ----> MnO2 + 4H+ + 2e-
Reduction: O3 + H2O ----> 2O2 + 2H+ + 2e-

am i right?

2007-04-30 20:14:34 · 2 answers · asked by Jimmy 3

NO2^−
CO2
CH3Cl
CO3^2−
ClO3^−

Is each either polar or nonpolar?
Could you kind of explain?
thank you

^ indicates start of superscript/ionic charge

2007-04-30 20:13:50 · 3 answers · asked by ojndoanj 3

A gaseous mixture consists of 6.59 g of N2, 4.07 g of O2, and 2.95 g of He. What volume does this mixture occupy at 21°C and 1.35 atm pressure?

2007-04-30 20:12:50 · 3 answers · asked by Anonymous

Given each of the following sets of values for an ideal gas, calculate the unknown quantity.
V = 619 mL; n = 0.0967 mol; T = 305 K. What is the pressure?

my answer is 3.909e-6

2007-04-30 20:08:27 · 2 answers · asked by Anonymous

from plants without the Bt gene (wild type)?

2007-04-30 20:06:38 · 1 answers · asked by davidk1978 1

What will be the new volume if 125 mL of He gas at 100°C and 0.983 atm is cooled to 24°C and the pressure is increased to 1.05 atm?

my answer is 52.2 mL

2007-04-30 20:06:21 · 4 answers · asked by Anonymous

I have an assignment and i need to know about the formation of fluorine in the stars!! I've searched everywhere on the internet and i can't find anything!!! Can any1 please help me out!

2007-04-30 20:06:16 · 1 answers · asked by rosypink 2

2007-04-30 19:43:57 · 3 answers · asked by King D 1

Need help for my Chem test, please explain how to solve these easy problems:

Find Ksp:
a) The solubility of CaC2O4 is 6.1*10^-3 g/L
b) The solubility of BiI3 is 1.32 *10^-5 g/L

2007-04-30 19:28:55 · 1 answers · asked by Spencer S 2

A) Divide the following into elements or compounds: O2, H2, H2O, Ar, CO2, CH4, C6H12O6.

B) The formula for ethanol is C2H5OH
i. How many types of atoms are there?
ii. How many atoms are there in total?
iii. What do the symbols C, H and O stand for?

C) How many atoms of each type are present in the following molecules:
i.NH3
ii. CH4
iii. CaCO3
iv. NaOH
v. Fe(OH)3
vi. KSCN

2007-04-30 19:24:38 · 4 answers · asked by Anonymous

If 6.00 L of an ideal gas is cooled from 51°C to -272°C, what will the volume of the gas become?

my answer is 0.0185 L

2007-04-30 19:24:07 · 2 answers · asked by Anonymous

A 1.24 L sample of gas at 759 mm Hg pressure is expanded until its volume is 2.02 L. What will be the pressure in the expanded gas sample (at constant temperature)?

my answer is 0.613 atm

2007-04-30 19:14:46 · 1 answers · asked by Anonymous

thanks

2007-04-30 18:58:44 · 7 answers · asked by a person 1

How much does one mole of moles weight!

puzzling question

And before you say do you're own homework, I can work this out, I just want to see who comes up with the most funniest answer,

2007-04-30 18:52:46 · 5 answers · asked by Mr Hex Vision 7

Help!

Can someone please explain what general trends there are in Ionisation Energies across the following series of metals:

Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn


I am having a hard time seeing the trends for the third ionisation energies only (not the first, and second).

Any help would be really appreciated.

2007-04-30 18:47:44 · 3 answers · asked by Emitrav 1

boilinng temprature of primary alkyl ammine is higher than corresponding hydrocarbons , alkyl halides but lower than corresponding alcohols
eg: methan < methyl choride

2007-04-30 18:28:29 · 1 answers · asked by sonu 1

Would prefer to have the full balanced chemcial equation instead of the ionic equation because it has to be used in titration calculations. Thanks. The formula for the reactants are: Ce(SO4)2 + Fe(NH4)2(SO4)2 --> ???

2007-04-30 17:59:11 · 2 answers · asked by Yoan 1

Suppose you wanted to produce 1 Liter of a 3.5 Molarity solution of H2SO4.
1) What is the solute?
2) What is the solvent?
3) How many grams of solute are needed to make this solution?
4) How many grams of solute are needed to make 2.5 L of a 1.75 M solution of Ba(NO3)2

2007-04-30 17:39:37 · 1 answers · asked by carmen 2

Say they are both at the same temperature, and you put an ice cube in a cup of acid and one in a cup of water, which would melt first?

2007-04-30 17:15:48 · 3 answers · asked by lilkrazyrae 1

Both of them are used in semiconductor industry.

2007-04-30 17:12:14 · 1 answers · asked by Anonymous