## Search found 149 matches

Thu Apr 22, 2021 9:55 pm
Forum: Chemistry forum
Topic: How to compute pH of ((COOH)2) Oxalic acid?
Replies: 3
Views: 102

### Re: How to compute pH of ((COOH)2) Oxalic acid?

What is the value of second equilibrium constant for HOOC-COOH? Is it 5.42e-5?
Thu Apr 22, 2021 9:51 pm
Forum: Chemistry forum
Topic: Finding out unknown compound in the solution and boiling point of the solution
Replies: 7
Views: 142

### Re: Finding out unknown compound in the solution and boiling point of the solution

We know that 1.286 g of the compound are dissolved in 25 g benzene, and therefore in 1000 g of benzene, there are 1.286 \times \frac{1000}{25}=51.44 g, \Delta T_{fp} = 5.50^\circ -3.27^\circ =2.23^\circ C; \Delta T_{fp} = K_{fp}\cdot m; m=\frac{\Delta T_{fp}}{K_{fp}}=\frac{2.23}{5.12}=0.436 m; \frac...
Thu Apr 22, 2021 5:21 am
Forum: Chemistry forum
Topic: Finding out unknown compound in the solution and boiling point of the solution
Replies: 7
Views: 142

### Re: Finding out unknown compound/element in the solution and boiling point of the solution

I am wrong. I modified wrongly the original question given by authors. Now I corrected the question and answer. You may check it now.
Thu Apr 22, 2021 1:01 am
Forum: Chemistry forum
Topic: Finding out unknown compound in the solution and boiling point of the solution
Replies: 7
Views: 142

### Finding out unknown compound in the solution and boiling point of the solution

After a sample of compound X weighing 1.286 g was dissolved in 25 g of C6H6, the freezing point of the resulting solution was found to be 3.27℃. What is the molecular weight of compound X? What is the name of solute compound? What is the boiling point of the solution? My answer: Molecular weight of ...
Wed Apr 21, 2021 6:55 am
Forum: Chemistry forum
Topic: How to compute pH of ((COOH)2) Oxalic acid?
Replies: 3
Views: 102

### How to compute pH of ((COOH)2) Oxalic acid?

pH of oxalic acid is given 5.4e-2 in table of equilibrium constants for acids and bases in aqueous solution. But, on other chemistry website , it is stated as '' The constant acid dissociation of oxalic acid is 5.60 between 10⁻² and 5.42 between 10⁻⁵. As oxalic acid is a polyprotic acid, there are t...
Mon Apr 19, 2021 9:19 pm
Forum: Chemistry forum
Topic: How to convert PPB to molarity?
Replies: 6
Views: 131

### Re: How to convert PPB to molarity?

Thanks for your guidance. After doing some chemistry work i got the correct answer. 20 ppb =0.2e-7 l = 0.2e-7 kg = 0.2e-7 × 10³ g=200.0 e-7 g ~ 1.0 e-7 M
Mon Apr 19, 2021 10:42 am
Forum: Chemistry forum
Topic: How to convert PPB to molarity?
Replies: 6
Views: 131

### Re: How to convert PPB to molarity?

So, my answer is also correct which is 1.09e-6 M/l. This solution is also like a water
Mon Apr 19, 2021 9:33 am
Forum: Chemistry forum
Topic: How to convert PPB to molarity?
Replies: 6
Views: 131

### Re: How to convert PPB to molarity?

But mol/Kg and mol/liter are inconsistent units. How did you make unit conversion?
Mon Apr 19, 2021 7:42 am
Forum: Chemistry forum
Topic: How to convert PPB to molarity?
Replies: 6
Views: 131

### How to convert PPB to molarity?

If any water reserve has lead concentration of 20 ppb, how is that = 1 × 10⁻⁷ M Pb²⁺.

My attempt: 20 ppb=x L/1 L solution → x= 20 × 10⁻⁹ L

Now density of

Pb²⁺=11.34 g/cm³ → 20ppb =1.09 × 10⁻⁶ M Pb

Where i am wrong?
Thu Apr 15, 2021 9:48 am
Forum: Chemistry forum
Topic: mystery substance
Replies: 6
Views: 215

### Re: mystery substance

Thu Apr 15, 2021 6:45 am
Forum: Chemistry forum
Topic: mystery substance
Replies: 6
Views: 215

### Re: mystery substance

Is the balanced chemical equation for the above chemical reaction correct?

3 HF + 2 HNO3 + 3 CH3COOH + 6Al → 2 Al2O3 + AlF3 + AlC6H9O6 + 4 H2 + N2
Thu Apr 15, 2021 1:56 am
Forum: Chemistry forum
Topic: mystery substance
Replies: 6
Views: 215

### Re: mystery substance

What is the equation and type of this chemical reaction?
Wed Apr 14, 2021 7:37 am
Forum: Chemistry forum
Topic: Coordination compound
Replies: 7
Views: 204

### Re: Coordination compound

Coordination compound means a compound in which a molecule or ion formed by the bonding of metal atom or ion to two or more ligands by coordinate covalent bonds Coordinate covalent bond means a bond formed when one atom provides both electrons in a shared pair. Ligand means an ion or neutral molecul...
Wed Apr 14, 2021 5:07 am
Forum: Chemistry forum
Topic: Coordination compound
Replies: 7
Views: 204

### Re: Coordination compound

In potassium ferrocyanide, there are five molecules of iron and potash cations and only six molecules of cyanide anion.
Wed Apr 14, 2021 12:30 am
Forum: Chemistry forum
Topic: Coordination compound
Replies: 7
Views: 204

### Re: Coordination compound

Two molecules of sulfate anions are attached to cations of potassium and aluminum. That's why it is called double salt.