Chemistry - September 2007

and why do substances butn in the air?

2007-09-25 10:16:17 · 3 answers · asked by Lauren 1

Which of the following would produce a basic aqueous solution?

A. P4O10
B. KCl
C. CO2
D. NH4Cl
E. none of these

2007-09-25 10:13:16 · 2 answers · asked by ChemChic 1

2007-09-25 10:09:31 · 1 answers · asked by bilinmz 1

2007-09-25 10:08:47 · 3 answers · asked by Chloe I 1

How can I make it stick to my brain. I need to know for tests.

2007-09-25 10:07:00 · 3 answers · asked by little bear 2

and also, what makes it acidic or basic? my teacher says if the oxygen is formed with a metal it is basic and a nonmetal it is acidic, but what if you have like PbHO or something with a metal AND a nonmetal paired with oxygen? im so confused and cant find help in my textbook or online :(

2007-09-25 10:02:28 · 6 answers · asked by Lauren 1

I've noticed that whenever they show a Tv screen or a computer screen(especially) on TV there always seem to be lines going across the screen from top to bottom (except in the highest quality video). Have you noticed that? What causes it?

2007-09-25 10:01:16 · 2 answers · asked by DichloroDiphenyl 5

Is HCl a polar compound?

2007-09-25 09:57:32 · 0 answers · asked by Anonymous

I dont know how how to approach to these question.

The mystery of the spinning pinwheel

Festive ornaments are usually made of metal. When the candles beneath the pin wheel are lit, the pinwheel begins to spin.


1) What energy transformation or transfers are occurring?

2) what property of the air is being applied to make this device work? (spin)

2007-09-25 09:52:02 · 1 answers · asked by dk 6

limestone rocks will be heated either by propane or a natural wood fire for a sweat lodge. once in the lodge they have water poured on them to give off steam. Do they give off dangerous gases?

2007-09-25 09:48:29 · 3 answers · asked by Neat Freak 1

How do i write a balanced dissociation reaction for each Ba_3(PO_4)_2 and BaCl_2, including appropriate charges on ions and indicating phases.

2007-09-25 09:44:38 · 2 answers · asked by Anonymous

Give me some examples as well plz to help!! Thnx!

2007-09-25 09:42:49 · 1 answers · asked by Anonymous

When potassium cyanide (KCN) reacts with acids, a deadly poisonous gas, hydrogen cyanide (HCN), is given off. Here is the equation below.

KCN(aq) + HCl(aq) KCl(aq) + HCN(g)
If a sample of 0.230 g of KCN is treated with an excess of HCl, calculate the amount of HCN formed, in grams.

Nitric oxide (NO) reacts instantly with oxygen gas to form nitrogen dioxide (NO2), a dark-brown gas.

2 NO(g) + O2(g) 2 NO2(g)
In one experiment 0.675 mole of NO is mixed with 0.378 mole of O2.
Calculate the number of moles of NO2 produced.

Consider the reaction below.

MnO2 + 4 HCl MnCl2 + Cl2 + 2 H2O
How many grams of Cl2 will be produced?

Titanium(IV) oxide (TiO2) is a white substance produced by the action of sulfuric acid on the mineral ilmenite (FeTiO3).

FeTiO3 + H2SO4 TiO2 + FeSO4 + H2O
It is opaque and its nontoxic properties make it suitable as a pigment in plastics and paints. In one process 9.90 103 kg of FeTiO3 yielded 1.80 103 kg of TiO2. What is the percent yield of the reaction?

2007-09-25 09:41:00 · 3 answers · asked by Sho V 1

Determine the empirical formulas for each of the following compounds, using the information given.
5.00g of aluminum metal is burned in excess oxygen to produce 9.45g of aluminum oxide.

2007-09-25 09:30:15 · 1 answers · asked by Anonymous

Determine the empirical formulas for each of the following compounds, using the information given.
2.46g of copper is reacted with excess chloride to produce 5.22g sample of copper chloride.

2007-09-25 09:28:47 · 2 answers · asked by Anonymous

what is...
to convert gas to liquid by cooling?

the prefix for 1/1000th

anything that has mass and takes up space

to measure the volume of an irregularly shaped object, we measure the ____ of water

you measure temperature in degrees______

unit to measure mass

the amount of space an object takes up

the amount of matter in an object

Point at the bottom of the curve of a liquid in a graduated cylinder

to separate matter into different parts by heating to

2007-09-25 09:23:22 · 2 answers · asked by nelliekellibelly 2

Electrons have to move around the nucleus and I have no idea how i'm going to make them move.

2007-09-25 09:18:28 · 3 answers · asked by peachygirl501 2

CAlculate the atomic mass for each of the following elements assuming that each consists of the isotopic mixture shown. Show all work on separate paper.

H: 99.985% 1^H; 0.015% 2^H

the 1^H part, i don't know how to type it, the 1 is small and goes to the top left of the H, same goes with 2^H

Can someone please tell me how to do this, cause i really don't understand it., thanks

2007-09-25 09:18:02 · 2 answers · asked by Anonymous

When solutions of silver nitrate and calcium chloride are mixed, silver chloride precipitates out of solution according to the equation

2AgNO(subscript 3)(aq) +CaCl(subscript 2)(aq) ------->2AgCl(s) + Ca(NO_3)(subscript 2) (aq)

Also
What is the concentration of this calcium chloride solution?

2007-09-25 09:04:32 · 1 answers · asked by Anonymous

Solid lithium hydroxide is used in space vehicles to remove exhaled carbon dioxide. The products are solid lithium carbonate and liquid water. What mass of carbon dioxide gas can 1119 g of lithium hydroxide absorb?
(Write the balanced chemical equation for the reaction first.)

2007-09-25 08:57:54 · 2 answers · asked by mgunterksu 1

Alright so you have cosmetics that's being tested on a a rat. The cosmetics would be the variable so what would be the control in this experiment?
Would it be a healthy untested rat?

2007-09-25 08:42:37 · 2 answers · asked by Scented Marker 2

The unbalanced equation for the problem is
MnO4(-)+HCO2H-->Mn(2+)+Co2
Ok, i know that the first couple of steps involve balancing the reaction in acidic conditions, but how does that help? In addition to that , what else do you need to do ?

2007-09-25 08:34:19 · 2 answers · asked by Ksp 2

Chemistry

2007-09-25 08:00:23 · 1 answers · asked by sunnydaze34509xoxo 2

What volume of a 0.986 M solution of NaOh must be added to 26.5 ml of 0.581 M hcl to completely neutralize the acid
How many moles of NaOh are needed for the neutralization?

2007-09-25 07:53:17 · 3 answers · asked by stranger 1

1H & 1H+
19F & 19F-
7LI & 23Na
7Li &9Be
12C&13C


PLease explain how you came up with this so i can learn. thank you

2007-09-25 06:33:28 · 4 answers · asked by ccutestuff2001 2

please help me!!
this is for my science project which is due tmrw !! :(

2007-09-25 06:19:25 · 3 answers · asked by oreaoranges 2

2007-09-25 06:15:55 · 1 answers · asked by Caramel 2

1. C + O2 ---> CO
2. Al + S8---> Al2 S3
3. K + B2 O5---> K2 O + B

2007-09-25 06:12:49 · 2 answers · asked by Anonymous

2007-09-25 06:10:16 · 2 answers · asked by Anonymous

Could you help?

2007-09-25 06:06:50 · 1 answers · asked by Caramel 2