I have an assessment about:
describe the main features of the environment occupied by Methanogen and identify the role of this organism in its ecosystem.
anyone has good link about it?

6)What is molarity of a solution that contains 212.5g of sodium nitrade(NaNO3) in 3 L of solution?

7) I must prepare 300.00 mL of 0.750 m NaBr solution by using 2.00 M NaBr stock solution. how many mL of stock solution should I use?

8)In order to dilute 1.0L of a 6.00M solution of NaOH to 0.500M solution, how much water to add?

9) What is concentration in percent by volume,%(v/v) of the following?
a)60.0 mL of methanol in a total volume of 500 mL
b)25.0 mL of rubbing alcohol (C3H7OH) diluted to a volume of 200.0 mL with water

10) How many grams of solute are needed to prepare:

I need to find the temp for hydrogen and chlorine, but where do you find it or what is it??

Find the volume of a gas at -30 C and 0.75 atm if it occupies a volume of 255L at 40.0 C and 1.25 atm.

I used the formula P1xV1/T1 = P2xV2/T2

and kept the pressure at 0.75 atm but are you supposed to keep it as STP and switch it to kPa??

The answer I got was
(o.75atm)(V1)/243k = (1.25atm)(255L)/313k

V1 = 330L

Is this right??

Hi I'm trying to answer these questions..
Find the number of atoms in
a) 52.5g of calcium metal
b) 1.5 mol of carbon
c) 1.5 mol of carbon dioxide

I have no idea where to start! How do you find the number of atoms?

could someone please check my work? Thank you. Note(some of these reactions may be reversible but I'm not sure if I have them right)

1. carbon dioxide gas is bubbled through a solution of lithium hydroxide.
CO2(g)+2LiOH(aq) ===> Li2CO3(aq)+ HOH(l)

2. Sodium nitrite is reacted with hydrochloric acid
NaNo2(aq)+HCl(aq) ===>NaCl(aq)+HNO2(aq)
(not reveresible, I think? right?)

3. carbon dioxide gas is reacted with solid potassium oxide
CO2(g)+K2O(s)===>K2CO3(?)

4. ammonium carbonate+potassium bromide
(NH4)2CO3(aq)+KBr(aq) <====> NH4Br(aq)+ K2CO3(aq)

The question calls for calculation of [H+] , Ka, PKa and Percent Ionization based on the PH measurement...

The Compound is Ammonium Acetate and the PH is 5.654

So far i have that the [H+} concentration is 2.22x10^-6

**im stuck on the other parts because i dont understand how to write the chemical equation for this...**

I am thinking that it is NH4CH3OOH <----> NH4 + CH3COO- + H+ (for whatever reason it looks wrong)

Im not sure please help.....

hi guys
thnx for your cool forum.I've an assessment which I have to complete for tommorow...and I couldnt find any thing useful.the assessment is:design an experiment to monitor level of mercury in our water ways
plz hlp me ...I couldnt find any thing!
plz just HLP me ...

I am having difficulties as to what equation to use to calculate the volume. Can someone please kindly give me some help?

What is the volume of 6M HCl required to acidify the mixture of 1g benzaldehyde and 2mL 10M KOH to a pH ~2?

MW of benzaldehyde is 106.1g/mol

cannizzaro reaction: benzaldehyde + KOH + H+ <=> benzoate + benzoic acid

pH = pKa + logQ <- I don't know if this is right to use....

First off, i really havent been paying attention in my class, so i really am not doing too hot in there. I have 4 questions that i need help on. or if you give me the equations i will solve them myself.
What mass of H2SO4 would be required to prepare 750mL of a 0.15M H2SO4 solution?
Determine the freezing point of a solution made by adding 27.5 g of Na2SO3 to 250.0 g of water.
If a saturated solution fo AgNO3 at 20C contains 216 g AgNO3 per 100.0 g of water, what mass of water could contain 725 g of this solute at the same temperature?